{"id":52,"date":"2018-03-28T19:58:49","date_gmt":"2018-03-28T23:58:49","guid":{"rendered":"https:\/\/pressbooks.bccampus.ca\/rmip3amed\/chapter\/6-1-overview-of-non-experimental-research\/"},"modified":"2018-03-28T20:21:12","modified_gmt":"2018-03-29T00:21:12","slug":"6-1-overview-of-non-experimental-research","status":"publish","type":"chapter","link":"https:\/\/pressbooks.bccampus.ca\/rmip3amed\/chapter\/6-1-overview-of-non-experimental-research\/","title":{"raw":"6.1 Overview of Non-Experimental Research","rendered":"6.1 Overview of Non-Experimental Research"},"content":{"raw":"\n<div class=\"bcc-box bcc-highlight\">\n<h3>Learning Objectives<\/h3>\n<ol class=\"c28 lst-kix_list_91-0 start\" start=\"1\">\n<li class=\"c7 c23 c36\"><span class=\"c13 c1\">Define non-experimental research, distinguish it clearly from experimental research, and give several examples.<\/span><\/li>\n<li class=\"c33 c23 c36\"><span class=\"c13 c1\">Explain when a researcher might choose to conduct non-experimental research as opposed to experimental research.<\/span><\/li>\n<\/ol>\n<\/div>\n<h2 class=\"c4\" style=\"text-align: left\"><strong><span class=\"c18 c1\">What Is Non-Experimental Research?<\/span><\/strong><\/h2>\n<p class=\"c4\"><strong><span class=\"c35 c1\">Non-experimental research<\/span><\/strong><span class=\"c1\">&nbsp;is research that lacks the manipulation of an independent variable. Rather than manipulating an independent variable, researchers conducting non-experimental research simply measure variables as they naturally occur (in the lab or real world).<\/span><\/p>\n<p class=\"c4\"><span class=\"c1\">Most researchers in psychology consider the distinction between experimental and non-experimental research to be an extremely important one. This is because although experimental research can provide strong evidence that changes in an independent variable cause differences in a dependent variable, non-experimental research generally cannot. As we will see, however, this inability to make causal conclusions does not mean that non-experimental research is less important than experimental research.<\/span><\/p>\n<h2 class=\"c4\" style=\"text-align: left\"><strong><span class=\"c18 c1\">When to Use Non-Experimental Research<\/span><\/strong><\/h2>\n<p class=\"c4\"><span class=\"c1\">As we saw in the last chapter<\/span><span class=\"c1\">, experimental research is appropriate when the researcher has a specific research question or hypothesis about a causal relationship between two variables\u2014and it is possible, feasible, and ethical to manipulate the independent variable. It stands to reason, therefore, that non-experimental research is appropriate\u2014even necessary\u2014when these conditions are not met. There are many times in which non-experimental research is preferred, including when:<\/span><\/p>\n<ul class=\"c28 lst-kix_list_92-0 start\">\n<li class=\"c4 c56 c36\"><span class=\"c15 c1\">the research question or hypothesis relates to a single variable rather than a statistical relationship between two variables (e.g., How accurate are people\u2019s first impressions?).<\/span><\/li>\n<li class=\"c4 c56 c36\"><span class=\"c15 c1\">the research question pertains to a non-causal statistical relationship between variables (e.g., is there a correlation between verbal intelligence and mathematical intelligence?).<\/span><\/li>\n<li class=\"c4 c56 c36\"><span class=\"c15 c1\">the research question is about a causal relationship, but the independent variable cannot be manipulated or participants cannot be randomly assigned to conditions or orders of conditions for practical or ethical reasons (e.g., does damage to a person\u2019s hippocampus impair the formation of long-term memory traces?).<\/span><\/li>\n<li class=\"c4 c56 c36\"><span class=\"c15 c1\">the research question is broad and exploratory, or is about what it is like to have a particular experience (e.g., what is it like to be a working mother diagnosed with depression?).<\/span><\/li>\n<\/ul>\n<p class=\"c4\"><span class=\"c1\">Again, the choice between the experimental and non-experimental approaches is generally dictated by the nature of the research question. Recall the three goals of science are to describe, to predict, and to explain. If the goal is to explain and the research question pertains to causal relationships, then the experimental approach is typically preferred. If the goal is to describe or to predict, a non-experimental approach will suffice. But the two approaches can also be used to address the same research question in complementary ways. For example, <\/span><span class=\"c1\"> Similarly, after his original study, Milgram conducted experiments to explore the factors that affect obedience. He manipulated several independent variables, such as the distance between the experimenter and the participant, the participant and the confederate, and the location of the study (Milgram, 1974)<\/span><span class=\"c22\">[footnote]Milgram, S. (1974). <em>Obedience to authority: An experimental view<\/em>. New York, NY: Harper &amp; Row.[\/footnote].<\/span><\/p>\n<h2 class=\"c4\" style=\"text-align: left\"><strong><span class=\"c18 c1\">Types of Non-Experimental Research<\/span><\/strong><\/h2>\n<p class=\"c4\"><span class=\"c1\">Non-experimental research falls into three broad categories: cross-sectional research, correlational research, and observational research.&nbsp;<\/span><\/p>\n<p class=\"c4\"><span class=\"c1\">First, <b>cross-sectional research&nbsp;<\/b>involves comparing two or more pre-existing groups of people. What makes this approach non-experimental is that there is no manipulation of an independent variable and no random assignment of participants to groups.<\/span> Imagine, for example, that a researcher administers the Rosenberg Self-Esteem Scale to 50 American college students and 50 Japanese college students. Although this \u201cfeels\u201d like a between-subjects experiment, it is a cross-sectional study because the researcher did not manipulate the students\u2019 nationalities. As another example, if we wanted to compare the memory test performance of a group of cannabis users with a group of non-users, this would be considered a cross-sectional study because for ethical and practical reasons we would not be able to randomly assign participants to the cannabis user and non-user groups. Rather we would need to compare these pre-existing groups which could introduce a selection bias (the groups may differ in other ways that affect their responses on the dependent variable). For instance, cannabis users are more likely to use more alcohol and other drugs and these differences may account for differences in the dependent variable across groups, rather than cannabis use per se.<\/p>\n<p class=\"c4\">Cross-sectional designs are commonly used by developmental psychologists who study aging and by researchers interested in sex differences. Using this design, developmental psychologists compare groups of people of different ages (e.g., young adults spanning from 18-25 years of age versus older adults spanning 60-75 years of age) on various dependent variables (e.g., memory, depression, life satisfaction). Of course, the primary limitation of using this design to study the effects of aging is that differences between the groups other than age may account for differences in the dependent variable. For instance, differences between the groups may reflect the generation that people come from (a cohort effect) rather than a direct effect of age. For this reason, longitudinal studies in which one group of people is followed as they age offer a superior means of studying the effects of aging. Once again, cross-sectional designs are also commonly used to study sex differences. Since researchers cannot practically or ethically manipulate the sex of their participants they must rely on cross-sectional designs to compare groups of men and women on different outcomes (e.g., verbal ability, substance use, depression). Using these designs researchers have discovered that men are more likely than women to suffer from substance abuse problems while women are more likely than men to suffer from depression. But, using this design it is unclear what is causing these differences. So, using this design it is unclear whether these differences are due to environmental factors like socialization or biological factors like hormones?<\/p>\n<div id=\"price_1.0-ch07_s02_s01\" class=\"section\">\n<p id=\"price_1.0-ch07_s02_s01_p04\" class=\"para editable block\">When researchers use a participant characteristic to create groups (nationality, cannabis use, age, sex), the independent variable is usually referred to as an <strong>experimenter-selected independent variable<\/strong> (as opposed to the experimenter-manipulated independent variables used in experimental research). Figure 6.1 shows data from a hypothetical study on the relationship between whether people make a daily list of things to do (a \u201cto-do list\u201d) and stress. Notice that it is unclear whether this is an experiment or a cross-sectional study because it is unclear whether the independent variable was manipulated by the researcher or simply selected by the researcher. If the researcher randomly assigned some participants to make daily to-do lists and others not to, then the independent variable was experimenter-manipulated and it is a true experiment. If the researcher simply asked participants whether they made daily to-do lists or not, then the independent variable it is experimenter-selected and the study is cross-sectional. The distinction is important because if the study was an experiment, then it could be concluded that making the daily to-do lists reduced participants\u2019 stress. But if it was a cross-sectional study, it could only be concluded that these variables are statistically related. Perhaps being stressed has a negative effect on people\u2019s ability to plan ahead. Or perhaps people who are more conscientious are more likely to make to-do lists and less likely to be stressed. The crucial point is that what defines a study as experimental or cross-sectional l is not the variables being studied, nor whether the variables are quantitative or categorical, nor the type of graph or statistics used to analyze the data. It is <em class=\"emphasis\">how<\/em> the study is conducted.<\/p>\n<div id=\"price_1.0-ch07_s02_s01_f01\">\n<p class=\"title\"><span class=\"title-prefix\">Figure 6.1<\/span>&nbsp;Results of a Hypothetical Study on Whether People Who Make Daily To-Do Lists Experience Less Stress Than People Who Do Not Make Such Lists<\/p>\n<p><a href=\"http:\/\/open.lib.umn.edu\/psychologyresearchmethods\/wp-content\/uploads\/sites\/171\/2015\/07\/bd7cd73d89fce5f35f92e02c09c858c5.jpg\"><img src=\"https:\/\/pressbooks.bccampus.ca\/rmip3amed\/wp-content\/uploads\/sites\/373\/2018\/03\/bd7cd73d89fce5f35f92e02c09c858c5.jpg\" alt=\"Results of a Hypothetical Study on Whether People Who Make Daily To-Do Lists Experience Less Stress Than People Who Do Not Make Such Lists\"><\/a><\/p>\n<\/div>\n<\/div>\n<div id=\"price_1.0-ch07_s02_s02\" class=\"section\">\n<p class=\"c4\"><span class=\"c1\">Second, the most common type of non-experimental research conducted in Psychology is correlational research. Correlational research is considered non-experimental because it focuses on the statistical relationship between two variables but does not include the manipulation of an independent variable. &nbsp;More specifically, in <strong><span class=\"c35 c1\">correlational&nbsp;research<\/span><\/strong>, the researcher measures two continuous variables with little or no attempt to control extraneous variables and then assesses the relationship between them. As an example, a researcher interested in the relationship between self-esteem and school achievement could collect data on students' self-esteem and their GPAs to see if the two variables are statistically related. Correlational research is very similar to cross-sectional research, and sometimes these terms are used interchangeably. The distinction that will be made in this book is that, rather than comparing two or more pre-existing groups of people as is done with cross-sectional research, correlational research involves correlating two continuous variables (groups are not formed and compared).<\/span><\/p>\n<\/div>\n<div class=\"section\"><\/div>\n<div class=\"section\">\n<p class=\"c4\"><span class=\"c1\">Third, &nbsp;<strong>observational research<\/strong>&nbsp;is non-experimental because it focuses on making observations of behavior in a natural or laboratory setting without manipulating anything. <\/span><span class=\"c1\">Milgram\u2019s original obedience study was non-experimental in this way. He was primarily interested in the extent to which participants obeyed the researcher when he told them to shock the confederate and he observed all participants performing the same task under the same conditions. The study by Loftus and Pickrell described at the beginning of this chapter is also a good example of observational research. The variable was whether participants \u201cremembered\u201d having experienced mildly traumatic childhood events (e.g., getting lost in a shopping mall) that they had not actually experienced but that the researchers asked them about repeatedly. In this particular study, nearly a third of the participants \u201cremembered\u201d at least one event. (As with Milgram\u2019s original study, this study inspired several later experiments on the factors that affect false memories.<\/span><\/p>\n<\/div>\n<div class=\"section\"><\/div>\n<div class=\"section\">\n<p class=\"c4\"><span class=\"c1\">The types of research we have discussed so far are all quantitative, referring to the fact that the data consist of numbers that are analyzed using statistical techniques. But as you will learn in this chapter, many observational research studies are more qualitative in nature. In&nbsp;<\/span><span class=\"c35 c1\">qualitative&nbsp;research<\/span><span class=\"c1\">, the data are usually nonnumerical and therefore cannot be analyzed using statistical techniques. Rosenhan\u2019s observational study of the experience of people in a psychiatric ward was primarily qualitative. The data were the notes taken by the \u201cpseudopatients\u201d\u2014the people pretending to have heard voices\u2014along with their hospital records. Rosenhan\u2019s analysis consists mainly of a written description of the experiences of the pseudopatients, supported by several concrete examples. To illustrate the hospital staff\u2019s tendency to \u201cdepersonalize\u201d their patients, he noted, \u201cUpon being admitted, I and other pseudopatients took the initial physical examinations in a semi-public room, where staff members went about their own business as if we were not there\u201d (Rosenhan, 1973, p. 256)<\/span><span class=\"c22\">[footnote]Rosenhan, D. L. (1973). On being sane in insane places. <em>Science, 179<\/em>, 250\u2013258.[\/footnote]. <\/span><span class=\"c1\">Qualitative data has a separate set of analysis tools depending on the research question. For example, thematic analysis would focus on themes that emerge in the data or conversation analysis would focus on the way the words were said in an interview or focus group.<\/span><\/p>\n<\/div>\n<h2 class=\"c4\" style=\"text-align: left\"><strong><span class=\"c18 c1\">Internal Validity Revisited<\/span><\/strong><\/h2>\n<p class=\"c4\"><span class=\"c1\">Recall that internal validity is the extent to which the design of a study supports the conclusion that changes in the independent variable caused any observed differences in the dependent variable.&nbsp;<\/span><span class=\"c22\">Figure 6.2<\/span><span class=\"c1\">&nbsp;shows how experimental, quasi-experimental, and non-experimental (correlational) research vary in terms of internal validity. Experimental research tends to be highest in internal validity because the use of manipulation (of the independent variable) and control (of extraneous variables) help to rule out alternative explanations for the observed relationships. If the average score on the dependent variable in an experiment differs across conditions, it is quite likely that the independent variable is responsible for that difference. Non-experimental (correlational) research is lowest in internal validity because these designs fail to use manipulation or control. <\/span><span class=\"c1\">Quasi-experimental research (which will be described in more detail in a subsequent chapter) is in the middle because it contains some, but not all, of the features of a true experiment. For instance, it may fail to use random assignment to assign participants to groups or fail to use counterbalancing to control for potential order effects. Imagine, for example, that a researcher finds two similar schools, starts an anti-bullying program in one, and then finds fewer bullying incidents in that \u201ctreatment school\u201d than in the \u201ccontrol school.\u201d While a comparison is being made with a control condition, the lack of random assignment of children to schools could still mean that students in the treatment school differed from students in the control school in some other way that could explain the difference in bullying (e.g., there may be a selection effect).<\/span><\/p>\n[caption id=\"attachment_388\" align=\"aligncenter\" width=\"900\"]<a href=\"http:\/\/opentextbc.ca\/researchmethods\/wp-content\/uploads\/sites\/37\/2015\/09\/7.1.png\"><img class=\"wp-image-388 size-full\" src=\"https:\/\/pressbooks.bccampus.ca\/researchmethodsinpsychology\/wp-content\/uploads\/sites\/63\/2016\/10\/7.1.png#fixme#fixme\" alt=\"Figure 7.1 Internal Validity of Correlational, Quasi-Experimental, and Experimental Studies. Experiments are generally high in internal validity, quasi-experiments lower, and correlational studies lower still.\" width=\"900\" height=\"177\"><\/a> Figure 6.2 Internal Validity of Correlation, Quasi-Experimental, and Experimental Studies. Experiments are generally high in internal validity, quasi-experiments lower, and correlation studies lower still.[\/caption]\n<p><span class=\"c1\">Notice also in&nbsp;<\/span><span class=\"c22\">Figure 6.2<\/span><span class=\"c1\">&nbsp;that there is some overlap in the internal validity of experiments, quasi-experiments, and correlational studies. For example, a poorly designed experiment that includes many confounding variables can be lower in internal validity than a well-designed quasi-experiment with no obvious confounding variables. Internal validity is also only one of several validities that one might consider, as noted in Chapter 5.<\/span><\/p>\n<div class=\"bcc-box bcc-success\">\n<h3>Key Takeaways<\/h3>\n<ul class=\"c28 lst-kix_list_93-0 start\">\n<li class=\"c7 c23 c36\"><span class=\"c66 c60 c1\">Non-experimental research is research that lacks the manipulation of an independent variable.<\/span><\/li>\n<li class=\"c7 c23 c36\"><span class=\"c66 c60 c1\">There are two broad types of non-experimental research. Correlational research that focuses on statistical relationships between variables that are measured but not manipulated, and observational research in which participants are observed and their behavior is recorded without the researcher interfering or manipulating any variables. <\/span><\/li>\n<li class=\"c7 c23 c36\"><span class=\"c66 c60 c1\">In general, experimental research is high in internal validity, correlational research is low in internal validity, and quasi-experimental research is in between.<\/span><\/li>\n<\/ul>\n<\/div>\n<div class=\"bcc-box bcc-info\">\n<h3>Exercises<\/h3>\n<ol class=\"c28 lst-kix_list_94-0 start\" start=\"1\">\n<li class=\"c7 c23 c36\"><span class=\"c10 c1\">Discussion: For each of the following studies, decide which type of research design it is and explain why.<\/span>\n<ol>\n<li class=\"c7 c23 c36\"><span class=\"c10 c1\">A researcher conducts detailed interviews with unmarried teenage fathers to learn about how they feel and what they think about their role as fathers and summarizes their feelings in a written narrative.<\/span><\/li>\n<li class=\"c7 c23 c36\"><span class=\"c10 c1\">A researcher measures the impulsivity of a large sample of drivers and looks at the statistical relationship between this variable and the number of traffic tickets the drivers have received.<\/span><\/li>\n<li class=\"c7 c23 c36\"><span class=\"c10 c1\">A researcher randomly assigns patients with low back pain either to a treatment involving hypnosis or to a treatment involving exercise. She then measures their level of low back pain after 3 months.<\/span><\/li>\n<li class=\"c7 c23 c36\"><span class=\"c10 c1\">A college instructor gives weekly quizzes to students in one section of his course but no weekly quizzes to students in another section to see whether this has an effect on their test performance.<\/span><\/li>\n<\/ol>\n<\/li>\n<\/ol>\n<\/div>\n\n","rendered":"<div class=\"bcc-box bcc-highlight\">\n<h3>Learning Objectives<\/h3>\n<ol class=\"c28 lst-kix_list_91-0 start\" start=\"1\">\n<li class=\"c7 c23 c36\"><span class=\"c13 c1\">Define non-experimental research, distinguish it clearly from experimental research, and give several examples.<\/span><\/li>\n<li class=\"c33 c23 c36\"><span class=\"c13 c1\">Explain when a researcher might choose to conduct non-experimental research as opposed to experimental research.<\/span><\/li>\n<\/ol>\n<\/div>\n<h2 class=\"c4\" style=\"text-align: left\"><strong><span class=\"c18 c1\">What Is Non-Experimental Research?<\/span><\/strong><\/h2>\n<p class=\"c4\"><strong><span class=\"c35 c1\">Non-experimental research<\/span><\/strong><span class=\"c1\">&nbsp;is research that lacks the manipulation of an independent variable. Rather than manipulating an independent variable, researchers conducting non-experimental research simply measure variables as they naturally occur (in the lab or real world).<\/span><\/p>\n<p class=\"c4\"><span class=\"c1\">Most researchers in psychology consider the distinction between experimental and non-experimental research to be an extremely important one. This is because although experimental research can provide strong evidence that changes in an independent variable cause differences in a dependent variable, non-experimental research generally cannot. As we will see, however, this inability to make causal conclusions does not mean that non-experimental research is less important than experimental research.<\/span><\/p>\n<h2 class=\"c4\" style=\"text-align: left\"><strong><span class=\"c18 c1\">When to Use Non-Experimental Research<\/span><\/strong><\/h2>\n<p class=\"c4\"><span class=\"c1\">As we saw in the last chapter<\/span><span class=\"c1\">, experimental research is appropriate when the researcher has a specific research question or hypothesis about a causal relationship between two variables\u2014and it is possible, feasible, and ethical to manipulate the independent variable. It stands to reason, therefore, that non-experimental research is appropriate\u2014even necessary\u2014when these conditions are not met. There are many times in which non-experimental research is preferred, including when:<\/span><\/p>\n<ul class=\"c28 lst-kix_list_92-0 start\">\n<li class=\"c4 c56 c36\"><span class=\"c15 c1\">the research question or hypothesis relates to a single variable rather than a statistical relationship between two variables (e.g., How accurate are people\u2019s first impressions?).<\/span><\/li>\n<li class=\"c4 c56 c36\"><span class=\"c15 c1\">the research question pertains to a non-causal statistical relationship between variables (e.g., is there a correlation between verbal intelligence and mathematical intelligence?).<\/span><\/li>\n<li class=\"c4 c56 c36\"><span class=\"c15 c1\">the research question is about a causal relationship, but the independent variable cannot be manipulated or participants cannot be randomly assigned to conditions or orders of conditions for practical or ethical reasons (e.g., does damage to a person\u2019s hippocampus impair the formation of long-term memory traces?).<\/span><\/li>\n<li class=\"c4 c56 c36\"><span class=\"c15 c1\">the research question is broad and exploratory, or is about what it is like to have a particular experience (e.g., what is it like to be a working mother diagnosed with depression?).<\/span><\/li>\n<\/ul>\n<p class=\"c4\"><span class=\"c1\">Again, the choice between the experimental and non-experimental approaches is generally dictated by the nature of the research question. Recall the three goals of science are to describe, to predict, and to explain. If the goal is to explain and the research question pertains to causal relationships, then the experimental approach is typically preferred. If the goal is to describe or to predict, a non-experimental approach will suffice. But the two approaches can also be used to address the same research question in complementary ways. For example, <\/span><span class=\"c1\"> Similarly, after his original study, Milgram conducted experiments to explore the factors that affect obedience. He manipulated several independent variables, such as the distance between the experimenter and the participant, the participant and the confederate, and the location of the study (Milgram, 1974)<\/span><span class=\"c22\"><a class=\"footnote\" title=\"Milgram, S. (1974). Obedience to authority: An experimental view. New York, NY: Harper &amp; Row.\" id=\"return-footnote-52-1\" href=\"#footnote-52-1\" aria-label=\"Footnote 1\"><sup class=\"footnote\">[1]<\/sup><\/a>.<\/span><\/p>\n<h2 class=\"c4\" style=\"text-align: left\"><strong><span class=\"c18 c1\">Types of Non-Experimental Research<\/span><\/strong><\/h2>\n<p class=\"c4\"><span class=\"c1\">Non-experimental research falls into three broad categories: cross-sectional research, correlational research, and observational research.&nbsp;<\/span><\/p>\n<p class=\"c4\"><span class=\"c1\">First, <b>cross-sectional research&nbsp;<\/b>involves comparing two or more pre-existing groups of people. What makes this approach non-experimental is that there is no manipulation of an independent variable and no random assignment of participants to groups.<\/span> Imagine, for example, that a researcher administers the Rosenberg Self-Esteem Scale to 50 American college students and 50 Japanese college students. Although this \u201cfeels\u201d like a between-subjects experiment, it is a cross-sectional study because the researcher did not manipulate the students\u2019 nationalities. As another example, if we wanted to compare the memory test performance of a group of cannabis users with a group of non-users, this would be considered a cross-sectional study because for ethical and practical reasons we would not be able to randomly assign participants to the cannabis user and non-user groups. Rather we would need to compare these pre-existing groups which could introduce a selection bias (the groups may differ in other ways that affect their responses on the dependent variable). For instance, cannabis users are more likely to use more alcohol and other drugs and these differences may account for differences in the dependent variable across groups, rather than cannabis use per se.<\/p>\n<p class=\"c4\">Cross-sectional designs are commonly used by developmental psychologists who study aging and by researchers interested in sex differences. Using this design, developmental psychologists compare groups of people of different ages (e.g., young adults spanning from 18-25 years of age versus older adults spanning 60-75 years of age) on various dependent variables (e.g., memory, depression, life satisfaction). Of course, the primary limitation of using this design to study the effects of aging is that differences between the groups other than age may account for differences in the dependent variable. For instance, differences between the groups may reflect the generation that people come from (a cohort effect) rather than a direct effect of age. For this reason, longitudinal studies in which one group of people is followed as they age offer a superior means of studying the effects of aging. Once again, cross-sectional designs are also commonly used to study sex differences. Since researchers cannot practically or ethically manipulate the sex of their participants they must rely on cross-sectional designs to compare groups of men and women on different outcomes (e.g., verbal ability, substance use, depression). Using these designs researchers have discovered that men are more likely than women to suffer from substance abuse problems while women are more likely than men to suffer from depression. But, using this design it is unclear what is causing these differences. So, using this design it is unclear whether these differences are due to environmental factors like socialization or biological factors like hormones?<\/p>\n<div id=\"price_1.0-ch07_s02_s01\" class=\"section\">\n<p id=\"price_1.0-ch07_s02_s01_p04\" class=\"para editable block\">When researchers use a participant characteristic to create groups (nationality, cannabis use, age, sex), the independent variable is usually referred to as an <strong>experimenter-selected independent variable<\/strong> (as opposed to the experimenter-manipulated independent variables used in experimental research). Figure 6.1 shows data from a hypothetical study on the relationship between whether people make a daily list of things to do (a \u201cto-do list\u201d) and stress. Notice that it is unclear whether this is an experiment or a cross-sectional study because it is unclear whether the independent variable was manipulated by the researcher or simply selected by the researcher. If the researcher randomly assigned some participants to make daily to-do lists and others not to, then the independent variable was experimenter-manipulated and it is a true experiment. If the researcher simply asked participants whether they made daily to-do lists or not, then the independent variable it is experimenter-selected and the study is cross-sectional. The distinction is important because if the study was an experiment, then it could be concluded that making the daily to-do lists reduced participants\u2019 stress. But if it was a cross-sectional study, it could only be concluded that these variables are statistically related. Perhaps being stressed has a negative effect on people\u2019s ability to plan ahead. Or perhaps people who are more conscientious are more likely to make to-do lists and less likely to be stressed. The crucial point is that what defines a study as experimental or cross-sectional l is not the variables being studied, nor whether the variables are quantitative or categorical, nor the type of graph or statistics used to analyze the data. It is <em class=\"emphasis\">how<\/em> the study is conducted.<\/p>\n<div id=\"price_1.0-ch07_s02_s01_f01\">\n<p class=\"title\"><span class=\"title-prefix\">Figure 6.1<\/span>&nbsp;Results of a Hypothetical Study on Whether People Who Make Daily To-Do Lists Experience Less Stress Than People Who Do Not Make Such Lists<\/p>\n<p><a href=\"http:\/\/open.lib.umn.edu\/psychologyresearchmethods\/wp-content\/uploads\/sites\/171\/2015\/07\/bd7cd73d89fce5f35f92e02c09c858c5.jpg\"><img decoding=\"async\" src=\"https:\/\/pressbooks.bccampus.ca\/rmip3amed\/wp-content\/uploads\/sites\/373\/2018\/03\/bd7cd73d89fce5f35f92e02c09c858c5.jpg\" alt=\"Results of a Hypothetical Study on Whether People Who Make Daily To-Do Lists Experience Less Stress Than People Who Do Not Make Such Lists\" \/><\/a><\/p>\n<\/div>\n<\/div>\n<div id=\"price_1.0-ch07_s02_s02\" class=\"section\">\n<p class=\"c4\"><span class=\"c1\">Second, the most common type of non-experimental research conducted in Psychology is correlational research. Correlational research is considered non-experimental because it focuses on the statistical relationship between two variables but does not include the manipulation of an independent variable. &nbsp;More specifically, in <strong><span class=\"c35 c1\">correlational&nbsp;research<\/span><\/strong>, the researcher measures two continuous variables with little or no attempt to control extraneous variables and then assesses the relationship between them. As an example, a researcher interested in the relationship between self-esteem and school achievement could collect data on students&#8217; self-esteem and their GPAs to see if the two variables are statistically related. Correlational research is very similar to cross-sectional research, and sometimes these terms are used interchangeably. The distinction that will be made in this book is that, rather than comparing two or more pre-existing groups of people as is done with cross-sectional research, correlational research involves correlating two continuous variables (groups are not formed and compared).<\/span><\/p>\n<\/div>\n<div class=\"section\"><\/div>\n<div class=\"section\">\n<p class=\"c4\"><span class=\"c1\">Third, &nbsp;<strong>observational research<\/strong>&nbsp;is non-experimental because it focuses on making observations of behavior in a natural or laboratory setting without manipulating anything. <\/span><span class=\"c1\">Milgram\u2019s original obedience study was non-experimental in this way. He was primarily interested in the extent to which participants obeyed the researcher when he told them to shock the confederate and he observed all participants performing the same task under the same conditions. The study by Loftus and Pickrell described at the beginning of this chapter is also a good example of observational research. The variable was whether participants \u201cremembered\u201d having experienced mildly traumatic childhood events (e.g., getting lost in a shopping mall) that they had not actually experienced but that the researchers asked them about repeatedly. In this particular study, nearly a third of the participants \u201cremembered\u201d at least one event. (As with Milgram\u2019s original study, this study inspired several later experiments on the factors that affect false memories.<\/span><\/p>\n<\/div>\n<div class=\"section\"><\/div>\n<div class=\"section\">\n<p class=\"c4\"><span class=\"c1\">The types of research we have discussed so far are all quantitative, referring to the fact that the data consist of numbers that are analyzed using statistical techniques. But as you will learn in this chapter, many observational research studies are more qualitative in nature. In&nbsp;<\/span><span class=\"c35 c1\">qualitative&nbsp;research<\/span><span class=\"c1\">, the data are usually nonnumerical and therefore cannot be analyzed using statistical techniques. Rosenhan\u2019s observational study of the experience of people in a psychiatric ward was primarily qualitative. The data were the notes taken by the \u201cpseudopatients\u201d\u2014the people pretending to have heard voices\u2014along with their hospital records. Rosenhan\u2019s analysis consists mainly of a written description of the experiences of the pseudopatients, supported by several concrete examples. To illustrate the hospital staff\u2019s tendency to \u201cdepersonalize\u201d their patients, he noted, \u201cUpon being admitted, I and other pseudopatients took the initial physical examinations in a semi-public room, where staff members went about their own business as if we were not there\u201d (Rosenhan, 1973, p. 256)<\/span><span class=\"c22\"><a class=\"footnote\" title=\"Rosenhan, D. L. (1973). On being sane in insane places. Science, 179, 250\u2013258.\" id=\"return-footnote-52-2\" href=\"#footnote-52-2\" aria-label=\"Footnote 2\"><sup class=\"footnote\">[2]<\/sup><\/a>. <\/span><span class=\"c1\">Qualitative data has a separate set of analysis tools depending on the research question. For example, thematic analysis would focus on themes that emerge in the data or conversation analysis would focus on the way the words were said in an interview or focus group.<\/span><\/p>\n<\/div>\n<h2 class=\"c4\" style=\"text-align: left\"><strong><span class=\"c18 c1\">Internal Validity Revisited<\/span><\/strong><\/h2>\n<p class=\"c4\"><span class=\"c1\">Recall that internal validity is the extent to which the design of a study supports the conclusion that changes in the independent variable caused any observed differences in the dependent variable.&nbsp;<\/span><span class=\"c22\">Figure 6.2<\/span><span class=\"c1\">&nbsp;shows how experimental, quasi-experimental, and non-experimental (correlational) research vary in terms of internal validity. Experimental research tends to be highest in internal validity because the use of manipulation (of the independent variable) and control (of extraneous variables) help to rule out alternative explanations for the observed relationships. If the average score on the dependent variable in an experiment differs across conditions, it is quite likely that the independent variable is responsible for that difference. Non-experimental (correlational) research is lowest in internal validity because these designs fail to use manipulation or control. <\/span><span class=\"c1\">Quasi-experimental research (which will be described in more detail in a subsequent chapter) is in the middle because it contains some, but not all, of the features of a true experiment. For instance, it may fail to use random assignment to assign participants to groups or fail to use counterbalancing to control for potential order effects. Imagine, for example, that a researcher finds two similar schools, starts an anti-bullying program in one, and then finds fewer bullying incidents in that \u201ctreatment school\u201d than in the \u201ccontrol school.\u201d While a comparison is being made with a control condition, the lack of random assignment of children to schools could still mean that students in the treatment school differed from students in the control school in some other way that could explain the difference in bullying (e.g., there may be a selection effect).<\/span><\/p>\n<figure id=\"attachment_388\" aria-describedby=\"caption-attachment-388\" style=\"width: 900px\" class=\"wp-caption aligncenter\"><a href=\"http:\/\/opentextbc.ca\/researchmethods\/wp-content\/uploads\/sites\/37\/2015\/09\/7.1.png\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-388 size-full\" src=\"https:\/\/pressbooks.bccampus.ca\/researchmethodsinpsychology\/wp-content\/uploads\/sites\/63\/2016\/10\/7.1.png#fixme#fixme\" alt=\"Figure 7.1 Internal Validity of Correlational, Quasi-Experimental, and Experimental Studies. Experiments are generally high in internal validity, quasi-experiments lower, and correlational studies lower still.\" width=\"900\" height=\"177\" \/><\/a><figcaption id=\"caption-attachment-388\" class=\"wp-caption-text\">Figure 6.2 Internal Validity of Correlation, Quasi-Experimental, and Experimental Studies. Experiments are generally high in internal validity, quasi-experiments lower, and correlation studies lower still.<\/figcaption><\/figure>\n<p><span class=\"c1\">Notice also in&nbsp;<\/span><span class=\"c22\">Figure 6.2<\/span><span class=\"c1\">&nbsp;that there is some overlap in the internal validity of experiments, quasi-experiments, and correlational studies. For example, a poorly designed experiment that includes many confounding variables can be lower in internal validity than a well-designed quasi-experiment with no obvious confounding variables. Internal validity is also only one of several validities that one might consider, as noted in Chapter 5.<\/span><\/p>\n<div class=\"bcc-box bcc-success\">\n<h3>Key Takeaways<\/h3>\n<ul class=\"c28 lst-kix_list_93-0 start\">\n<li class=\"c7 c23 c36\"><span class=\"c66 c60 c1\">Non-experimental research is research that lacks the manipulation of an independent variable.<\/span><\/li>\n<li class=\"c7 c23 c36\"><span class=\"c66 c60 c1\">There are two broad types of non-experimental research. Correlational research that focuses on statistical relationships between variables that are measured but not manipulated, and observational research in which participants are observed and their behavior is recorded without the researcher interfering or manipulating any variables. <\/span><\/li>\n<li class=\"c7 c23 c36\"><span class=\"c66 c60 c1\">In general, experimental research is high in internal validity, correlational research is low in internal validity, and quasi-experimental research is in between.<\/span><\/li>\n<\/ul>\n<\/div>\n<div class=\"bcc-box bcc-info\">\n<h3>Exercises<\/h3>\n<ol class=\"c28 lst-kix_list_94-0 start\" start=\"1\">\n<li class=\"c7 c23 c36\"><span class=\"c10 c1\">Discussion: For each of the following studies, decide which type of research design it is and explain why.<\/span>\n<ol>\n<li class=\"c7 c23 c36\"><span class=\"c10 c1\">A researcher conducts detailed interviews with unmarried teenage fathers to learn about how they feel and what they think about their role as fathers and summarizes their feelings in a written narrative.<\/span><\/li>\n<li class=\"c7 c23 c36\"><span class=\"c10 c1\">A researcher measures the impulsivity of a large sample of drivers and looks at the statistical relationship between this variable and the number of traffic tickets the drivers have received.<\/span><\/li>\n<li class=\"c7 c23 c36\"><span class=\"c10 c1\">A researcher randomly assigns patients with low back pain either to a treatment involving hypnosis or to a treatment involving exercise. She then measures their level of low back pain after 3 months.<\/span><\/li>\n<li class=\"c7 c23 c36\"><span class=\"c10 c1\">A college instructor gives weekly quizzes to students in one section of his course but no weekly quizzes to students in another section to see whether this has an effect on their test performance.<\/span><\/li>\n<\/ol>\n<\/li>\n<\/ol>\n<\/div>\n<hr class=\"before-footnotes clear\" \/><div class=\"footnotes\"><ol><li id=\"footnote-52-1\">Milgram, S. (1974). <em>Obedience to authority: An experimental view<\/em>. New York, NY: Harper &amp; Row. <a href=\"#return-footnote-52-1\" class=\"return-footnote\" aria-label=\"Return to footnote 1\">&crarr;<\/a><\/li><li id=\"footnote-52-2\">Rosenhan, D. L. (1973). On being sane in insane places. <em>Science, 179<\/em>, 250\u2013258. <a href=\"#return-footnote-52-2\" class=\"return-footnote\" aria-label=\"Return to footnote 2\">&crarr;<\/a><\/li><\/ol><\/div>","protected":false},"author":64,"menu_order":1,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[48],"contributor":[],"license":[],"class_list":["post-52","chapter","type-chapter","status-publish","hentry","chapter-type-numberless"],"part":50,"_links":{"self":[{"href":"https:\/\/pressbooks.bccampus.ca\/rmip3amed\/wp-json\/pressbooks\/v2\/chapters\/52","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pressbooks.bccampus.ca\/rmip3amed\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/pressbooks.bccampus.ca\/rmip3amed\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/rmip3amed\/wp-json\/wp\/v2\/users\/64"}],"version-history":[{"count":1,"href":"https:\/\/pressbooks.bccampus.ca\/rmip3amed\/wp-json\/pressbooks\/v2\/chapters\/52\/revisions"}],"predecessor-version":[{"id":112,"href":"https:\/\/pressbooks.bccampus.ca\/rmip3amed\/wp-json\/pressbooks\/v2\/chapters\/52\/revisions\/112"}],"part":[{"href":"https:\/\/pressbooks.bccampus.ca\/rmip3amed\/wp-json\/pressbooks\/v2\/parts\/50"}],"metadata":[{"href":"https:\/\/pressbooks.bccampus.ca\/rmip3amed\/wp-json\/pressbooks\/v2\/chapters\/52\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/pressbooks.bccampus.ca\/rmip3amed\/wp-json\/wp\/v2\/media?parent=52"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/rmip3amed\/wp-json\/pressbooks\/v2\/chapter-type?post=52"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/rmip3amed\/wp-json\/wp\/v2\/contributor?post=52"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/rmip3amed\/wp-json\/wp\/v2\/license?post=52"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}