AP Psychology Chapter AP Psychology Chapter TwoTwo

Methods of Methods of ResearchResearch

How do How do psychologists psychologists collect data collect data about behavior?about behavior?

Clever Hans!Clever Hans!

Regardless of the method Regardless of the method used, all research is based used, all research is based on the Scientific Method of on the Scientific Method of PsychologyPsychology

ScientificScientific means means systematic, testable, and systematic, testable, and objective.objective.

What are the three What are the three main principles main principles that guide the that guide the Scientific Method Scientific Method of Psychology?of Psychology?

Step 1 – Step 1 – TheoryTheoryStep 2 – Step 2 – HypothesesHypothesesStep 3 – Step 3 – Research Research and Observationand Observation

TheoriesTheories organize known organize known facts and summarizes current facts and summarizes current research in the field. research in the field.

Theories are Theories are a well-a well-

substantiatsubstantiated ed

explanation explanation of existing of existing

data. data. E.g – Low self-esteem leads to depressionE.g – Low self-esteem leads to depression

A A hypothesishypothesis is a is a testable testable predictionprediction based on what is known based on what is known or what is “theorized”.or what is “theorized”.

They let us reject or They let us reject or revise our theory.revise our theory.I Feel So Dumb I

Can’t Do Anything!

Eg: Eg: People with low self-People with low self-esteem score higher esteem score higher

on a depression scale.on a depression scale.

Research or observation Research or observation or experimentsor experiments are are generated to collect data, which generated to collect data, which then goes into evaluating the then goes into evaluating the hypothesis, which may or may hypothesis, which may or may not add to the existing theory.not add to the existing theory.

What are the two What are the two broad types of broad types of research that research that psychologists psychologists conduct?conduct?

Research DesignsResearch DesignsQuantitative and Quantitative and

Qualitative ResearchQualitative Research

Quantitative researchQuantitative research emphasizes emphasizes numbers,numbers, measurements, deductive measurements, deductive logic, statistics, control, and logic, statistics, control, and experiments.experiments.

It is very It is very objectiveobjective and all about and all about the numbers and hard data!the numbers and hard data!

.

Quantitative researchQuantitative research researchers use tools, researchers use tools, such as questionnaires such as questionnaires or equipment to collect or equipment to collect

numericalnumerical data and data and statisticsstatistics

.

It is very It is very objectiveobjective and all about the and all about the

numbers and hard numbers and hard data!data!

Qualitative researchQualitative research emphasizes natural emphasizes natural settings, observation, settings, observation, understanding, themes, understanding, themes, verbal narratives, and verbal narratives, and flexible designs.flexible designs.

QualitativeQualitative data is in the data is in the form of words, pictures or form of words, pictures or objects. objects.

It is much more It is much more subjectivesubjective and results are based on and results are based on observation and observation and interpretation.interpretation.

What are some What are some examples of examples of qualitative qualitative research research methods?methods?

Naturalistic Naturalistic ObservationObservation

Naturalistic Observation Naturalistic Observation Study behavior in its Study behavior in its natural context. natural context. Spontaneous Spontaneous behavior in a behavior in a subject’s subject’s naturalnatural environment. environment.

No interaction with No interaction with the subject.the subject.

Is this natural?

IE. If you want to study the IE. If you want to study the interactive behavior of a specific interactive behavior of a specific breed of gorillas, you would need breed of gorillas, you would need to go to where the gorillas live in to go to where the gorillas live in nature (not a zoo). nature (not a zoo).

You would need to observe them You would need to observe them without their knowledge, and without their knowledge, and without manipulating anything. without manipulating anything.

What are some What are some potential potential problems with problems with this type of this type of research?research?

BiasBias Situation in which a Situation in which a

factor unfairly factor unfairly increases the increases the likelihood of a likelihood of a researcher reaching a researcher reaching a particular conclusionparticular conclusion

Example of BiasExample of Bias I am researching teenagers I am researching teenagers behavior and I was recently behavior and I was recently mugged by a group of mugged by a group of teenagers… am I likely to teenagers… am I likely to observe teenage behaviors as observe teenage behaviors as being motivated by evil versus being motivated by evil versus good? good?

Why?Why?

Case StudiesCase Studies

Case StudyCase StudyIn depth study of one individual In depth study of one individual

with the hopes of determining with the hopes of determining universal principlesuniversal principles

Case studies often Case studies often include face-to-face include face-to-face interviews, paper and interviews, paper and pencil tests, and more.pencil tests, and more.

Case StudyCase Study In depth study of one In depth study of one

individual with the individual with the hopes of determining hopes of determining universal principlesuniversal principles

Very open to biasVery open to bias

Difficulty of applying Difficulty of applying data from one person to data from one person to everyoneeveryone

IE. I want to know why Bart IE. I want to know why Bart killed thirty-five people over killed thirty-five people over a twenty-year period of a twenty-year period of time. I will examine the time. I will examine the police files, observe and police files, observe and interview Bart, talk to his interview Bart, talk to his and the victims families, etc.and the victims families, etc.

Difficulty of applying data from one person to everyoneDifficulty of applying data from one person to everyonebias, etcbias, etc

What are some What are some potential potential problems with problems with this type of this type of research?research?

SurveysSurveys

Survey MethodSurvey MethodResearch method that Research method that

relies on self-reports; uses relies on self-reports; uses questionnaires, interviews.questionnaires, interviews.

Usually a very Usually a very efficient and efficient and inexpensiveinexpensive method to method to collect a lot of information collect a lot of information and create basic and create basic assumptions about assumptions about behaviors. behaviors.

When Creating A SurveyWhen Creating A SurveyQuestions need precise Questions need precise

answersanswersLanguage and wording must Language and wording must

be simplebe simple– IE. 77% of New Yorkers where interested in IE. 77% of New Yorkers where interested in

plants and trees, but only 39% where plants and trees, but only 39% where interested in botany; 48% where interested interested in botany; 48% where interested in fossils, but only 39% where interested in in fossils, but only 39% where interested in paleontology; 42% where interested in rocks paleontology; 42% where interested in rocks and minerals, but 53% where interested in and minerals, but 53% where interested in GeologyGeology

When Creating A SurveyWhen Creating A Survey Ask questions that won’t embarrass Ask questions that won’t embarrass

or humiliateor humiliate Responders will lie if there is a Responders will lie if there is a

perceived punishment – Anonymity is perceived punishment – Anonymity is keykey

Don’t ask morally ambiguous Don’t ask morally ambiguous questions – keep it simple and to the questions – keep it simple and to the pointpoint

Who the interviewer is will affect the Who the interviewer is will affect the responders answersresponders answers

When Creating A SurveyWhen Creating A Survey Shortly phrased questions. Shortly phrased questions.

– IE. As you know, the term Holocaust IE. As you know, the term Holocaust usually refers to the killing of usually refers to the killing of millions of Jews in Nazi death millions of Jews in Nazi death camps during WWII. Does it seem camps during WWII. Does it seem possible or does it seem impossible possible or does it seem impossible to you that the Nazi extermination to you that the Nazi extermination of the Jew never happened?of the Jew never happened?

– 1 out of 5 Gallup poll responders said that the Holocaust never 1 out of 5 Gallup poll responders said that the Holocaust never happened due to the phrasing of the questionhappened due to the phrasing of the question

When Creating A SurveyWhen Creating A SurveyHot Topics/Key Words:Hot Topics/Key Words:

–IE. Do you favor an IE. Do you favor an amendment amendment prohibiting prohibiting abortionsabortions? <50% opposed OR ? <50% opposed OR Do you favor an amendment Do you favor an amendment protecting the lifeprotecting the life of an of an unborn child? >70%unborn child? >70%

When Creating A SurveyWhen Creating A SurveyLimited Answer OptionsLimited Answer OptionsOrder of Questions – easier to Order of Questions – easier to

more difficult works bestmore difficult works bestFright Terms – avoid using Fright Terms – avoid using

terms with big repercussions terms with big repercussions – IE. Use Problem V. Crisis, Past V. IE. Use Problem V. Crisis, Past V. Dead, Dealt With V. PunishDead, Dealt With V. Punish

– Use a RANDOM SAMPLE (more on Use a RANDOM SAMPLE (more on that later…)that later…)

False Consensus Effect False Consensus Effect

Skews the Skews the reports by reports by jumping to jumping to large large conclusions conclusions that fit into our that fit into our pre-conceived pre-conceived ideas.ideas.

Tendency to Tendency to overestimate the extent overestimate the extent to which others share to which others share our beliefs and our beliefs and behaviors. behaviors.

CorrelationCorrelation

Correlational StudyCorrelational StudyResearch study designed Research study designed

to determine the degree to determine the degree to which two variables to which two variables are are relatedrelated to one to one anotheranother

IE. What is the IE. What is the relationship relationship between exercise between exercise and weight? and weight? Smoking and Smoking and cancer? Brain cancer? Brain size and size and intelligence? intelligence? Education and Education and level of income? level of income?

Is there a Is there a correlatiocorrelatio

n?n?

What are some What are some potential potential problems with problems with this type of this type of research?research?

Watch out for Watch out for illusory correlationsillusory correlations!!

Does sugar make kids more Does sugar make kids more hyper?hyper?

Does a full moon make people act Does a full moon make people act crazier?crazier?

Does going outside with no coat Does going outside with no coat on mean you will catch a cold?on mean you will catch a cold?

Which is the more likely hand?Which is the more likely hand?

Which is a more likely hand?Which is a more likely hand?

1 in 2,598,960

Which is the more likely hand?Which is the more likely hand?

1 in 2,598,960 1 in 2,598,960

We often We often perceive order perceive order

in random in random events!events!

Correlational StudyCorrelational Study

Correlation studies DO Correlation studies DO NOT prove causation.NOT prove causation. They can only They can only suggestsuggest that there is or is not a that there is or is not a relationshiprelationship between the between the two variables.two variables.

IE. IE. – A correlation study may A correlation study may suggest that people who suggest that people who earn higher levels of earn higher levels of education generally earn education generally earn higher salaries, but it higher salaries, but it can’t definitively say can’t definitively say that getting a degree that getting a degree will get you a higher will get you a higher paying job. paying job.

IE. Student scores on the SAT are IE. Student scores on the SAT are collected, as are senior year GPA’s. collected, as are senior year GPA’s.

We want to see if a high GPA We want to see if a high GPA correlates to a high SAT score. correlates to a high SAT score.

We can’t say one causes the other, We can’t say one causes the other, but we can imply that students but we can imply that students who have high/low GPA’s score who have high/low GPA’s score high/low on SAT’s. high/low on SAT’s.

Can we use GPA as a predictor of SAT performance?

But But Remember….Remember…. Correlation Correlation Does Not Does Not

Imply Imply Causation!Causation!

Graphing Graphing Correlation Correlation

RelationshipsRelationships

After you plot the data the After you plot the data the slope (direction) of the line slope (direction) of the line indicates whether or not there indicates whether or not there is a positive, negative, or no is a positive, negative, or no relationship between relationship between variables.variables.

How close the dots are How close the dots are together indicates how close together indicates how close the relationship between the the relationship between the variables is.variables is.

PositivePositive Correlation Correlation

As the value of one As the value of one variable increases (or variable increases (or decreases) so does the decreases) so does the value of the other value of the other variable.variable.

Studying and GradesStudying and Grades–As students study more, their grades As students study more, their grades

increase.increase.Practice and AthleticsPractice and Athletics

–As athletes practice more, their batting As athletes practice more, their batting averages increaseaverages increase

Dieting and Weight LossDieting and Weight Loss–As dieters ate less, their weight dropped.As dieters ate less, their weight dropped.

NegativeNegative Correlation CorrelationAs the value of one variable As the value of one variable

increases, the value of the other increases, the value of the other variable decreases.variable decreases.–The more you exercise, the less you The more you exercise, the less you

weighweigh–The more you study, the less your The more you study, the less your

teachers yell at youteachers yell at you

ZeroZero Correlation Correlation

There is no relationship There is no relationship whatsoever between the two whatsoever between the two variables.variables.–The length of your hair has no The length of your hair has no

influence on your level of influence on your level of intelligence.intelligence.

Correlational StudyCorrelational Study Important NOT to imply a cause and Important NOT to imply a cause and

effect relationship between the effect relationship between the variablesvariables

Correlational study does not Correlational study does not determine determine whywhy the two variables are the two variables are related--just that they are related.related--just that they are related.

Correlational studies are helpful in Correlational studies are helpful in making predictions.making predictions.

Experiment Experiment An investigation seeking to An investigation seeking to

understand relations of understand relations of cause cause and effect. and effect.

The experimenter changes a The experimenter changes a variable (cause), and in turn variable (cause), and in turn changes another variable changes another variable (effect). (effect).

At the same time the At the same time the experimenter hopes to hold all of experimenter hopes to hold all of the other variables constantthe other variables constant

Experiment Experiment

An An investigatioinvestigation seeking to n seeking to understand understand relations of relations of cause and cause and

effecteffect. .

The experimenter changes a variable

(cause), which in turn changes another variable (effect).

At the same time the experimenter hopes to

hold all of the other variables constant so that they can attribute

any changes to the manipulation.

IE. I want to know if new drug IE. I want to know if new drug AA will help will help to alleviate the symptoms of insomnia. to alleviate the symptoms of insomnia.

Patients will be given different doses at Patients will be given different doses at different times to see what works and different times to see what works and what doesn’t. what doesn’t.

I need to control other factors, like I need to control other factors, like mattress softness and room temperature, mattress softness and room temperature, to eliminate them as causes of sleep to eliminate them as causes of sleep deprivation.deprivation.

How do I create How do I create a valid and a valid and reliable reliable experiment?experiment?

Step 1:Step 1: Choose a Choose a HypothesisHypothesis

A hypothesis expresses a A hypothesis expresses a relationship between two variables. relationship between two variables. (it’s a testable prediction – (it’s a testable prediction – remember?)remember?)

IE. My hypothesis is that IE. My hypothesis is that watching watching violent television programs violent television programs makes people more aggressive.makes people more aggressive.

Step Two:Step Two: Choose Variables Choose VariablesVariables are things that Variables are things that

are measured, controlled, are measured, controlled, or manipulated in or manipulated in research.research.Type of television

program, violent behavior, environment, participants, etc…

The The independentindependent variable variable is the manipulated is the manipulated variablevariable..

IE. IE. The The type of TV type of TV programprogram viewed is viewed is the independent the independent variable because I variable because I can adjust what can adjust what shows are viewed, shows are viewed, for how long, by for how long, by whom, etc.whom, etc.

IE. Measuring the change in IE. Measuring the change in aggression levels is the aggression levels is the

dependent variable in our dependent variable in our experiment because it changes experiment because it changes

based on what is viewed, for how based on what is viewed, for how long, etc.long, etc.

The The dependentdependent variable is measured variable is measured for change.for change.

Step Three:Step Three: OperationalizeOperationalize

When you operationalize When you operationalize your variables, you are your variables, you are defining defining them and them and explaining how you will explaining how you will measuremeasure them. them.

IE. The operational definition of the independent variable (what defines a violent show?) scenes of fighting, bloodshed, use of weapons, etc

IE. The operational definition of the dependent variable (what defines an increase in aggressive behavior?) would be an increase in agitation or tenseness, increased vocal volume, threats of bodily harm, kicks, punches, throwing objects, etc.

Step Four:Step Four: Identify Potential Identify Potential Extraneous Extraneous

Variables/Confounding Variables/Confounding VariablesVariables

Any factor or variable that Any factor or variable that causes an effect (or potential causes an effect (or potential affects) other than the affects) other than the variable being studied is variable being studied is considered an extraneous considered an extraneous variable and must be variable and must be eliminated or accounted for…eliminated or accounted for…

IE. An extraneous variable IE. An extraneous variable in our experiment would in our experiment would be a phone call from a be a phone call from a solicitor during a program, solicitor during a program,

the viewer receiving mail the viewer receiving mail including a poor report including a poor report card,card,

a viewer stubbing their a viewer stubbing their toe during a show, alcohol toe during a show, alcohol abuse, etc. abuse, etc.

All of these could increase All of these could increase aggressiveness, but are aggressiveness, but are not related to viewing not related to viewing violent television.violent television.

Step Five:Step Five: Identify Who You Will Identify Who You Will Be TestingBe Testing

The individuals on which the The individuals on which the research will be conducted are research will be conducted are called called subjectssubjects (or participants). (or participants).

A small group of subjects are drawn A small group of subjects are drawn from a larger potential from a larger potential populationpopulation..

IE. Our subjects will be drawn from IE. Our subjects will be drawn from the overall population of 12the overall population of 12thth grade grade males at Appo. High School.males at Appo. High School.

Step Six:Step Six: How Do We Decide Who How Do We Decide Who Will Be Subjects, and Who Won’t?Will Be Subjects, and Who Won’t?

Since we can’t Since we can’t realistically test all realistically test all 1212thth grade males at grade males at Appo. High School, Appo. High School, we have to create we have to create a representative a representative sample of the sample of the population so that population so that we can generalize we can generalize our findings to the our findings to the whole group.whole group.

Method 1: Rigorous Method 1: Rigorous Control DesignControl Design

Designing an experiment Designing an experiment with specific, hand-picked with specific, hand-picked groups in mind.groups in mind.

IE. Only testing males, 18 IE. Only testing males, 18 years old, in AP Psychology.years old, in AP Psychology.

Method 2: Sample Method 2: Sample DesignDesign

A A samplesample is a representation of the is a representation of the entire population. entire population.

A A random samplerandom sample allows that allows that every every

member of an overall population member of an overall population has an equal chance to be in the has an equal chance to be in the sample. sample.

IE. Drawing names from a hat.IE. Drawing names from a hat.

Method 3: Stratified SampleMethod 3: Stratified Sample Subdivide the population into at Subdivide the population into at

least two different subpopulations least two different subpopulations that share the same characteristicsthat share the same characteristics, , then draw a random sample from then draw a random sample from each group.each group.

IE. Surveying views on Equal Rights. IE. Surveying views on Equal Rights. Split your human population into Split your human population into men and women, and then randomly men and women, and then randomly draw eight men’s and women’s draw eight men’s and women’s names.names.

Method 4: Systematic Method 4: Systematic SampleSample Select a starting point from your Select a starting point from your

population and then select every ?th population and then select every ?th participant.participant.

IE. Merck corporation wants test the IE. Merck corporation wants test the effectiveness of a new aspirin on their effectiveness of a new aspirin on their 100,000 employees. Get a roster of 100,000 employees. Get a roster of employees, start at #1, and then employees, start at #1, and then choose every 100choose every 100thth name on the list. name on the list.

Method 5: Cluster SamplingMethod 5: Cluster SamplingDivide your population into Divide your population into multiple multiple

subgroupssubgroups, randomly choose a , randomly choose a subgroup to test, and then test the subgroup to test, and then test the entire population of that subgroup.entire population of that subgroup.

IE. Split the country up into geographic IE. Split the country up into geographic regions (East Coast, Midwest, etc.). regions (East Coast, Midwest, etc.). Randomly choose a region to test, and Randomly choose a region to test, and then test every person in those statesthen test every person in those states..

Method 6: Convenience Method 6: Convenience SamplingSampling

Use a population that is Use a population that is readily available.readily available.

IE. Test your neighbors, your IE. Test your neighbors, your family, your co-workers, a family, your co-workers, a passer-by on the street.passer-by on the street.

Step Seven:Step Seven: AssignmentAssignment

Once you have chosen Once you have chosen your subjects to study, your subjects to study, you must assign them to you must assign them to one of one of twotwo groups; those groups; those that that will bewill be “manipulated”, and those “manipulated”, and those that that won’t.won’t.

Group 1: Experimental Group 1: Experimental GroupGroup

The The experimental experimental groupgroup receives the receives the independent variable independent variable and is manipulated and is manipulated throughout the throughout the experiment.experiment.

IE. In our television violence IE. In our television violence experiment, those in the experiment, those in the experiment groupexperiment group will watch will watch varying degrees of varying degrees of violent violent program, for varying lengths of program, for varying lengths of time, etc., and their changes in time, etc., and their changes in levels of aggression measured.levels of aggression measured.

Group 2: Control GroupGroup 2: Control GroupThe The control groupcontrol group does not receive does not receive the independent the independent variable.variable.

IE. In our television violence IE. In our television violence experiment, the experiment, the control groupcontrol group will be shown a variety of will be shown a variety of non-violentnon-violent programming in programming in order to create a baseline to order to create a baseline to compare the experiment compare the experiment group against.group against.

PlaceboPlacebo

A non-active substance or condition A non-active substance or condition administered instead of a drug or administered instead of a drug or active agentactive agent

Given to the control groupGiven to the control group Sugar pill in the test made Sugar pill in the test made to look like the to look like the SmartPill SmartPill ™™

How Do We Choose Our How Do We Choose Our Subjects?Subjects?

Method 1: Random Method 1: Random AssignmentAssignment Random assignmentRandom assignment (don’t (don’t

confuse with random sample) confuse with random sample) means that the subjects have an means that the subjects have an equal chance of being placed into equal chance of being placed into each group. If we allow subjects each group. If we allow subjects to choose their own group, we to choose their own group, we may have a may have a subject-relevant subject-relevant confounding variable.confounding variable.

Subject-Relevant Subject-Relevant Confounding VariablesConfounding Variables

A A subject-relevant confounding subject-relevant confounding variable variable would allow those would allow those people that liked violent people that liked violent movies or were prone to movies or were prone to violence already to choose to violence already to choose to be in the experimental group. be in the experimental group.

What’s wrong with that?What’s wrong with that?

Blind procedureBlind procedure

To help avoid this confounding To help avoid this confounding variable, we prescribe a variable, we prescribe a single-single-blind designblind design. The subjects are . The subjects are “blind” to whether they have “blind” to whether they have been randomly placed in the been randomly placed in the control or experiment group.control or experiment group.

The researcher would know who is The researcher would know who is getting the getting the SmartPill SmartPill ™ ™ but not but not the participantthe participant

Double Blind ProcedureDouble Blind Procedure An experimental procedure where An experimental procedure where

both the research participants and both the research participants and those collecting the data are those collecting the data are ignorant (blind) to the expected ignorant (blind) to the expected outcome of the experimentoutcome of the experiment

(the people handing out the pills nor the people taking the pills know who actually got the SmartPill ™

Method 2: Group Matching Method 2: Group Matching When assigning members When assigning members

to the experiment or to the experiment or control group, it is control group, it is important that the important that the characteristics of both characteristics of both groups need to be as groups need to be as similar as possible.similar as possible.

IE. After rigorously or randomly IE. After rigorously or randomly determining our subjects, as determining our subjects, as many white, black, tall, short, many white, black, tall, short, overweight, slim members overweight, slim members should be in the control group as should be in the control group as there are in the experiment there are in the experiment group.group.

Was the experiment Was the experiment reliablereliable?? (did you get the results (did you get the results

you expected)you expected)

Can the experiment be Can the experiment be replicatedreplicated? (can someone else ? (can someone else conduct the same experiment conduct the same experiment

and get similar results?and get similar results?

Was the experiment a Was the experiment a success?success?

REMEMBER !!!REMEMBER !!!

Only experimental data Only experimental data can conclusively can conclusively

demonstrate causal demonstrate causal relations between relations between

variables variables (A causes B to (A causes B to

happen).happen).

Step Eight:Step Eight: Address Other Address Other Potential Issues With Potential Issues With

ExperimentsExperiments Situation-relevant confounding variablesSituation-relevant confounding variables

refer to making sure that the situations refer to making sure that the situations that the experiment and control groups are that the experiment and control groups are placed in are exactly the same. We must placed in are exactly the same. We must have have equivalent environmentsequivalent environments..

IE. We cannot have those watching violent IE. We cannot have those watching violent films in a large auditorium, and those films in a large auditorium, and those viewing sitcoms in a small living room.viewing sitcoms in a small living room.

Experimenter BiasExperimenter BiasExperimenter BiasExperimenter Bias occurs when the occurs when the

experimenter unconsciously treats experimenter unconsciously treats members of the control and members of the control and experiment groups differently, which experiment groups differently, which increases the chances of confirming increases the chances of confirming their hypothesis.their hypothesis.

IE. The experimenter gives soda to the control IE. The experimenter gives soda to the control group, and beer to the violent viewers. The group, and beer to the violent viewers. The experimenter speaks more abruptly with the experimenter speaks more abruptly with the violence crowd (inciting them?).violence crowd (inciting them?).

To help avoid this type of To help avoid this type of confounding variable, we confounding variable, we employ a employ a double-blind designdouble-blind design, , where neither the subjects where neither the subjects nor the researcher may know nor the researcher may know which is the control or the which is the control or the experiment group. A third-experiment group. A third-party has the appropriate party has the appropriate records so that the date can records so that the date can be analyzed later.be analyzed later.

The The Hawthorne EffectHawthorne Effect refers refers to the fact that some subjects to the fact that some subjects will alter their behaviors will alter their behaviors simply because they know simply because they know that they are part of an that they are part of an experiment, regardless of experiment, regardless of what is being done to them.what is being done to them.

The The Placebo EffectPlacebo Effect refers to the refers to the phenomenon that a patient's phenomenon that a patient's symptoms can be alleviated by symptoms can be alleviated by an otherwise ineffective an otherwise ineffective treatment, apparently because treatment, apparently because the individual expects or the individual expects or believes that it will work.believes that it will work.

Hindsight BiasHindsight Bias is the is the tendency to believe, once the tendency to believe, once the outcome is already known of outcome is already known of course, that you would have course, that you would have foreseen it…that even foreseen it…that even though it's over and you though it's over and you know the outcome, you knew know the outcome, you knew it all along.it all along.

OverconfidenceOverconfidence occurs when we occurs when we tend to think that we know more tend to think that we know more than we do. Make over-than we do. Make over-generalizations when reporting generalizations when reporting results, forcing results into results, forcing results into preconceived hypothesis to say preconceived hypothesis to say “I told you so”, instead of letting “I told you so”, instead of letting the results speak for themselves, the results speak for themselves, etc.etc.

BiasBias

The tendency to notice The tendency to notice evidence which supports one evidence which supports one particular point of view or particular point of view or hypothesishypothesis

Researcher BiasResearcher Bias

The tendency to The tendency to notice evidence notice evidence which supports one which supports one particular point of particular point of view or hypothesisview or hypothesis

Example of Researcher BiasExample of Researcher Bias

If my hypothesis is that excessive If my hypothesis is that excessive sugar intake causes poor test sugar intake causes poor test performance, I will readily conclude performance, I will readily conclude this as fact when three students this as fact when three students who failed the test were observed who failed the test were observed drinking a soda prior to the test. drinking a soda prior to the test. Other students who failed and other Other students who failed and other factors are ignored.factors are ignored.

Participant BiasParticipant Bias

Tendency of research subjects to Tendency of research subjects to respond in certain ways because respond in certain ways because they know they are being they know they are being observed. The subjects might try observed. The subjects might try to behave in ways they believe to behave in ways they believe the researcher wants them to the researcher wants them to behave.behave.

Once I have Once I have completed my completed my research, how do I research, how do I present my present my findings ?findings ?