Methods of Empirical Research

8/13/2019 Methods of Empirical Research

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Research MethodsApproaches to studying human

behavior using the scientific method(systematic, empirical observation)


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During this presentation, you will be asked some questions.

Make sure you stop to reflect on the answers tothese questions before going on to the next slide.Review the PowerPoint presentation, pages in thetext, or talk to classmates to find the answers toquestions that you arent sure of.Bring any REMAINING questions (for which you

dont have answers) to our next class.


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In this PowerPoint presentation,were going to be looking at fivemethods of empirical research


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The type of question in which

youre interested might influencewhich of the research methodsyou would be more likely to use.


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In the next slide, you will beasked to choose one of fivequestions about people. As we

go through each of the differentresearch methods, you should

think about how well eachmethod would work in answeringthe question you have chosen.


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Choose one of the followingquestions about people:

Do women get more emotional than men whenthey do poorly on an exam?How do people choose where and with whom tosit in Marbeck Commons?What is it like to be an international student atBluffton University?Do students participate more in morning or inafternoon classes?What sorts of food items would students be mostinterested in having Marbeck serve?


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The five research methods well be looking at are.

Naturalistic observationCase studies

Surveys & InterviewsQuasi-experimentControlled experiments


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A couple of comments before weget started

This presentation reviews & expands upon thereading from your text (Module 2). You shouldread those pages either before or along with this

PowerPoint presentationThese five methods sometimes overlap, and thereare not clean distinctions between them. Also,sometimes researchers use some combination of

these approaches. Still the categories can help youto recognize different general approaches togathering empirical data.


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Naturalistic ObservationSystematically observing people in theirnatural environment, e.g., in a classroom, intheir living rooms, on a street corner, in ashopping mall, etc.Though we all observe people, naturalisticobservation can be made more systematic

by the following processes:Clear conceptualization and operationalization of variables


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Wait a minute!!!!WHAT do conceptualization and

operationalization mean???And WHAT is a variable?


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Good question!!! Here aresome definitions!!!

A variable is the thing that youreinterested in studying likedepression or gender or levels of

emotionality (how emotionalsomeone is) or different types of

food!


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To conceptualize avariable means to get clearabout what you mean by

the variable.

For example, for the variable food type,you need to be clear about whether you

mean (1) vegetarian or meat, OR(2) breakfast, lunch or dinner foods, OR

(3) Ethiopian, Thai or American foods, OR(4) something else!


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By the way, things like depression, gender,level of emotionality and food type, etc. arecalled variables because they vary .

Some people are more depressed than othersSome people are men, and others are womenSome people are less emotional than othersFood types can range from pizza to hamburgers tofilet mignon, or might be Thai, Ethiopian, Polishor American cuisine, etc., etc.


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To operationalize a variable isto decide how you will measure it

If the variable youre studying is intelligence &you dont think GPA is a good measure ofintelligence, what measure WILL you use?Asking these sorts of questions is completing the

process of operationalizing your variables.By the way, conceptualization &

operationalization are necessary for ALL thedifferent research methods (not just for naturalisticobservation)


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Naturalistic Observation(As I was saying) though we all observe

people, naturalistic observation can be mademore systematic by the following processes:

Clear conceptualization and operationalizationof variablesSystemized procedures for recording observed

behaviorMultiple observers who check each othersobservations & work


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Case StudyIn depth study of an individual or small group ofindividuals

Notice that the study is in depth!! Some case

studies involve spending hours, days, months,years with a particular person to understand themthoroughlyUsed most often in study of rare phenomena, e.g.,

people with particular types of brain damage orother rare conditions, serial killers, particularlycreative people or people with other rare abilities,etc.


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Surveys/Interviews

Questioning individuals through paper & pencil, phone interviews or face-to-face

interviewsMay ask about just one variable or maygather information on multiple variables inan attempt to study the relationship betweenthem


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Controlled Experiments& Quasi-Experimental Designs

(At this point, were going to look atthese two designs together, focusing

on the similarities between them.Later on in this presentation, well

talk about how they differ)


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Controlled Experiments& Quasi-Experimental Designs

The main type of experiment that weregoing to look at involves comparing two or

more groups. The groups differ on somevariable(s) called INDEPENDENTVARIABLES--and the effect of thosevariables on other variables calledDEPENDENT VARIABLES-- is beingstudied through the experiment.


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Some new terms: Independentand Dependent Variables

The independent variable is the variable that theresearcher thinks is the CAUSE of some othervariables (i.e., the hypothesized cause).

The dependent variable is the effect being studied.The researcher wants to figure out what causes thedependent variableIn other words, the researcher is hypothesizingthat the independent variable causes the dependentvariable and is doing her experiment to test thishypothesis.


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Independent and DependentVariables

To make sure you understand this, thinkabout the experiment that Dr. Nath did in

class--where two students (one male & onefemale) had to try to catch a ruler droppedthrough their fingers

What was the independent variable in thisexperiment?What was the dependent variable?


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Independent and Dependent Variables inthe Class Demonstration

The independent variable was GENDERThe dependent variable was REACTION TIME(i.e., how quick the ruler was caught)

You know this because the hypothesis was that gender causes differences in

reaction time The experimenter believes that the CAUSE of

different reaction times is gender. The CAUSE is the independent variable. The EFFECT is the dependent variable.


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Lets try another one to make sureyou understand these terms

Dr. Nath wrote the following question on the board:Why do some students succeed academically (whereasothers fail)? In this question, are we approaching

academic success as an independent variable or adependent variable?

In this question, academic success is a DEPENDENTvariable because were trying to figure out what causes it.

If we believe that having clear goals causes some people tosucceed in school whereas others fail, then we are interestedin studying the presence or absence of clear goals as anindependent variable, a possible CAUSE of academic successor failure.

OK back to


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OKback toControlled Experiments& Quasi-Experimental Designs

In these sorts of experiments, the groups DIFFERon the independent variable and the researcher

then looks at whether the groups ALSO DIFFERon the dependent variable.If the hypothesis is true, then they do. If theydont, then the hypothesis must not be true. Doyou understand why this is the case? (If not, askabout this in class)


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How do Controlled ExperimentalDesigns & quasi-experiments differ?

In the controlled experimental design, theresearcher controls the administration of

the independent variable and then measuresthe dependent variable

F l l t i gi h


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For example, lets imagine a researcherwho is interested in the following

hypothesis: Hypothesis: Students who study for tests instudy groups do better on their testsGiven this hypothesis, what are theindependent & dependent variables?

The researcher believes that study groupsCAUSE improved academic performance.

SOthe independent variable is study groupsand the dependent variable is academic performance


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Hypothesis: Students who study for testsin study groups do better on their tests

In controlled experimental design, theresearcher CONTROLS the administration

of the independent variable, meaning thatshe decides (controls) who will be in studygroups and who wont.


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Some more terms. There are some subjects who are administered theindependent variable (in this case, study groups)and some subjects who arent

The group of subjects to whom the independentvariable is administered is called the experimentalgroup.The other group is called the control group.

The control group and the experimental groupshould be the same in all other ways. The onlyway in which they should differ is on theindependent variable.


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The control group and the experimentalgroup should be the same in all other

ways. The only way in which theyshould differ is on the independentvariable.

Do you remember what happened in theexperiment I did in class? How did NOTfollowing this rule create problems?

NOT following this rule meant that there were

extraneous variables that might be alternativeexplanations for the findings, so the researchercouldnt REALLY know if the independentvariable was responsible for any differences on the

dependent variable or not.


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As we just said, in controlled experimentaldesigns, the researcher controls what subjectsreceive the independent variable and what subjects

dont and in doing so, forms the groups. In contrast, in quasi-experimental designs ,the researcher studies groups thatALREADY have preexisting differences.The groups differ on the independentvariable, but the researcher doesntCONTROL this difference between the

groups.


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Now can you see why the experiment we did inclass was quasi-experimental rather thancontrolled experimental design?

In fact, can you see why you cant usecontrolled experimental design to study genderas an independent variable?Can you think of any other variables that you

would need to use quasi-experimental (ratherthan a controlled experiment) if you wereinterested in studying them as independentvariables?


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Well talk a little bit later about theimplications of these differences.

S i h l fl h


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Some questions to help you reflect on thevalue & limitations of each of these

methods. One of these methods is limited because itinvolves studying only a small number of people,and so this may be a problem if we want to

generalize the results (i.e., applied to other peoplewho havent been studied). Which of thesemethods would be most susceptible to this

problem?

Note that this research method would be unlikelyto be used if the researcher is particularlyinterested in generalizing to a larger group of

people?

S i h l fl h


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methods. One of these methods is limited to only studyingthings that can be observed and cant be used (forexample) to study how someone THINKS aboutsomething. Which of these methods might this betrue for?As was noted earlier, one of these methods can not

be used to study any independent variables that theresearcher can not realistically or ethicallycontrol. Do you remember which one?

S i h l fl h


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methods. One of these research methods is particularly good when youre studyingsomething that its important to understandin the context in which it occurs in order toreally understand it (e.g., like gang

behavior). Which research method wouldthat be?

S i h l fl h


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methods. One of these research methods depends a loton self- report, and so if youre studyingsomething that people might not be willingto tell you OR something about people thatthey might not be able to tell you (that theydont really understand about themselves),then you would be less likely to use thismethod. What method would that be?


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Which of the five researchmethods would you be most

likely to use to address thequestion that you chose

toward the beginning of thisPowerPoint presentation?

Tip: Thinking about how the questions onthe preceding slides apply to the research

question you chose should help you toanswer this question.


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Youll want to review the answers

for each question, (not just yourown) given on the following slides b/c it should help you understand

each of the methods a bit better.


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Do women get more emotional than menwhen they do poorly on an exam?

Which research methods could you use to answerthis question?

For this question, you are unlikely to use a case

study, and you are UNABLE to use a controlledexperimental design. Do you know why eachof these is true?

Naturalistic observation, surveys/interviews, or

a quasi-experimental design would all be possible approaches to answering this question.How would each of these approaches provide asomewhat different answer to this same

research question?


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How do people choose where and withwhom to sit in Marbeck Commons?

For this question, you are unlikely to use a casestudy, a quasi-experiment or a controlledexperimental design. Why?

Naturalistic observation or surveys/interviewswould be the most likely methods that you woulduse.

What would be some of the drawbacks of surveysor interviews that naturalistic observation wouldavoid?


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What is it like to be an internationalstudent at Bluffton University?

For this question, it would be impossible to do acontrolled experimental design--for the same reasonits impossible for the question about gender &emotionality. Do you know why?Youre also unlikely to use naturalistic observation orquasi-experimental design. Can you imagine why?The most likely approach that would be used in

studying this question would be case studies orsurveys/interviews. Why? Note that being an international student at BlufftonUniversity is rare (meaning, there are not large numbersto study) case studies are used most often in studying rare

phenomenon.


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Do students participate more inmorning or in afternoon classes?

For this question, youre unlikely to use a casestudy. Why?Any of the other approaches is possible! Which doyou think would work best? Why?

Of the four, I think the strongest case could bemade for using either naturalistic observation or

controlled experimental design. What would bethe benefits of each approach? What about thelimitations?


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What sorts of food items would students bemost interested in having Marbeck serve?

For this question, a researcher is unlikely touse a case study, a quasi-experiment or a

controlled experiment. Do you know why?Either naturalistic observation orsurveys/interviews would be possible.

Which do you think is best & why?


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What design is the best one to use to answer thequestion: which sorts of menus would students be

most interested in having Marbeck serve?In naturalistic observation, you would watchstudents in Marbeck & see what menu items theychoose. In what ways might this limit the answersyou find?

What students choose to eat in Marbeck may not be the best measure of what they are interested in havingserved; they may be most interested in some items that

are not available.Because of this limitation, naturalistic observationmay not be the best approach.


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What design is the best one to use to answerthe question: which sorts of menus would

students be most interested in having Marbeckserve?

The most likely, & probably best method would be to complete surveys or interviews.When the question involves peoples opinions,surveys/interviews are the most common research

method that is used. They provide the means for alarge group of people to provide informationregarding what their opinions are.


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A few more words about things toconsider about a few of theseresearch methods.


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In Surveys/Interviews

The wording used for the questions is veryimportant. A minor change in wordingmight result in very different answers.Who you choose to survey or interview isvery important.

Researchers rarely interview ALL the people inwhich they are interested

Wh h


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Who you choose to survey orinterview is very important.

For example, you may want to know whatBluffton University students prefer to eat in thecafeteria, but you will probably NOT ask each &

every Bluffton student in finding this out.Instead, researchers survey or interview a smallernumber of people (called a sample) who areexpected to represent the entire group of people in

which you are interested (the population).Researchers then generalize the answer they getfrom the sample to the population. For this towork, the choice of the sample is critical.

Th h i f h l i


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The choice of the sample iscritical.

The sample must be large enough in order forthe researcher to be able to generalize to the

population. (I shouldnt interview two students

and then say what all Bluffton students think!)The sample also needs to be representative ofthe population, so for example, I shouldnt justtalk to seniors. or to men or to white

students or to religious students, etc. If I aminterested in saying something about ALLBluffton students, I need to talk to a sample of

people that adequately represents all of thedifferences in the population.


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Surveys/InterviewsCan be used to describe how a certain group feelsabout a variable or variables OR can be used to tryto study the relationship between two variables

(e.g., an independent & dependent variable)Surveys/interviews have some problems withdoing the latter, e.g., proving anything about cause& effect. This is because they yield correlationaldata.

WHAT i l i l


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WHAT is correlationaldata?????

A correlation is a relationship between twovariables. When two variables arecorrelated, that means they are related toeach other in one of two ways:

Positive correlation: as one of the variablesincreases, so does the other

Negative correlation: as one of the variablesincreases, the other decreases


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Correlational DataTwo variables can be positively or negativelycorrelated or not correlated at all (unrelated)

Note that negative correlations indicate thatthere IS a relationship between the variables,the relationship is just an inverse one.

It is a fact that studies have found a


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correlation between the number of churches ina town & the number of bars.

Would you expect this correlation to be positive ornegative?Actually, although it is different from what most

people expect, the correlation between the # of bars & the # of churches is a positive one--themore churches there are, the more bars there are.(A negative correlation would mean that the morechurches, the LESS bars there are.)Does this mean that going to church makes

people more likely to frequent bars??? Possibly but can you think of any other possible

explanations for this relationship?


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Positive correlation between the # churches bars other possible explanations

It is also possible that going to bars maymake people more likely to go to church!This too would result in a positivecorrelation.However, heres a hint: The most likelyexplanation for this relationship is that thereis a THIRD VARIABLE that influences

both the # of churches & the # of bars.


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Positive correlation between the # churches bars other possible explanations

The size of the population is a third variable that is positively correlated to both of these othervariables and probably explains why they are

related to one another.Rather than going to church making it more likelyto go to bars OR vice versa, it is more likely thatthe larger the population size, the more churches

there are AND the larger the population size, themore bars there are. So when you find a lot of bars, you also find a lot of churches although probably neither of them causes the other.

C l ti d NOT


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Correlation does NOT meancausation

Correlation tells us nothing about thedirection of the relationship between twovariables or whether either of them reallycauses the other

Correlation does NOT mean


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Correlation does NOT meancausation

When A & B are correlated, there are a number of possible explanations of the relationship betweenA & B. As weve seen in our example, these

include the possibility that:A causes BB causes AC causes A AND C causes B (where C issome third variable an EXTRANEOUSvariable)A & B are reciprocally related, i.e., they bothCAUSE the other (its impossible to knowwhich came first, like the chicken & the egg)

Surveys/interviews yield


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Surveys/interviews yieldcorrelational data

Because of this, they do not providedefinitive answers regarding causation.The SAME is true for each of the otherresearch methods weve reviewed EXCEPTFOR controlled experimental design.How does controlled experimental design

get around this problem? How does it yieldresults that are more than just correlational?

Controlled experimental design can say


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p g ysomething about cause (whereas correlationaldata cant) BECAUSE:

It controls or deals with extraneousvariables

How does it do this?

How does controlled experimental


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pdesign eliminate or deal with extraneousvariables?

First, it eliminates as many extraneous variables asit can by standardizing the experimental procedureso that all groups experience the same thing

For example, as we have discussed, placebo (suchas sugar pills) are sometimes used to make surethe control & experimental group do not differ onthe extraneous variable of believing the treatment

will work. Placebos make sure that ALL groupshave this same belief. Remember the goal is tomake EVERYTHING is the same between theexperimental and the control group EXCEPT forthe independent variable?

How does controlled experimental


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pdesign eliminate or deal with extraneousvariables?

Secondly, it does this through the way itassigns subjects to groups.

Subjects are assigned to groups throughrandom assignment.What is random assignment?


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Random AssignmentIn random assignment, each subject has an equallikelihood of ending up in either of the groups.Because subjects are randomly assigned, any

preexisting extraneous variables are spreadequally between the two groups. Because theextraneous variables are split between the groupsequally, they can not explain the reason for any

differences that exist between the control & theexperimental group at the end of the experiment.The only thing that can explain the difference

between the groups is the independent variable because its the only way the groups differed.

So.Controlled experimental design can say


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something about cause (whereas correlationaldata cant) BECAUSE:

It controls or deals with extraneous variablesANDIn controlled experimental design, the researcheradministers the independent variable so weKNOW that it is the independent variable that iscausing the dependent variable and not the otherway around. (By administering the independentvariable, the chicken & the egg problem areeliminated.)


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Now that youre done with

this presentation. You should be able to answer all the

questions that I asked within the presentation, AND.


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If you have completed this presentation, know the

answers to the questions inthe presentation, and have

finished reading the text, youare now ready to take the quizon Jenzabar..

Good luck!!!


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Methods of Empirical Research

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