RESEARCH METHODS Modules 2 and 3. Class Experiment This is a study of some factors that may affect the solution of anagrams or scrambled words. A list

RESEARCH METHODS Modules 2 and 3

Class Experiment This is a study of some factors that may affect the solution of anagrams or scrambled words. A list of letter combinations that can be unscrambled to create common English words will be presented. No proper (capitalized) nouns, abbreviations, or foreign words appear. Solve each anagram in the spaces below. If you are having difficulty, raise your hand. I will give you a hint. Example: DORWAnswer __________________

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Class Experiment This is a study of some factors that may affect the solution of anagrams or scrambled words. A list of letter combinations that can be unscrambled to create common English words will be presented. No proper (capitalized) nouns, abbreviations, or foreign words appear. Solve each anagram in the spaces below. If you are having difficulty, raise your hand. I will give you a hint. Example: DORWAnswer __________________

ExperimentReview General Topic of study: effect of perceptual set on solving of anagrams. What was the research question? What was the hypothesis? How was the hypothesis tested? What were the results? Alternative explanation of results and errors?

NEW SUBTOPIC: INTRODUCTION Modules 2 and 3: Research Methods

Introduction How do we gain knowledge? Sensory experience but can be undependable and incomplete Agreement with others but majority does not always = truth Expert opinion but no one knows everything Logic but rational explanations not always best/true Scientific method thats the one

Introduction How do we gain knowledge (contd) Scientific method Includes rigorous testing of hypothesis and public nature of procedures and conclusions Systematic testing of hypothesis, gathering of data, and analysis Steps: Form a question (usually from theory, event, daily experience) State hypothesis (educated guess of answer to question) Test hypothesis (systematic way of getting answer) Report results (replication if repeated and same results, more likely true) Example of why use scientific method? Question: If someone confessed to a murder in an online newsgroup would you notify the police? When simply asked, 56.4% of subjects said they would When experimentally tested (had it occur), only 3 of 200 newsgroup members notified police

The Scientific Method The scientific method is the process of testing our ideas about the world by: setting up situations that test our ideas. making careful, organized observations. analyzing whether the data fit with our ideas. If the data dont fit our ideas, then we modify our ideas, and test again.

Introduction Goals of research Describe Explain Predict Control (causation) Research design (how study is set up) influences what type of conclusions you can reach.

Introduction Important general terminology Hypothesis: specific statement of expected results Testable prediction Subjects: persons/animals on whom study is conducted

Introduction Important terms (contd) Sample and population Population: all possible members of group Sample: representative subgroup of pop. Want sample to be representative. If representative, then can generalize to pop. How to make sample representative? Random sample: every member of pop has = chance of being selected Stratified sample: take representative subgroups in proportions as they exist in pop Sampling: process by which Ss are selected Random assignment: when members of random sample are assigned randomly to experimental or control group

Introduction Imp. terms (contd) Variable: characteristic or factor that can assume different values (changes) Examples stress, alcohol use, gender, etc. What we study in psychological research Not the subjects (people in the study) what you study in them Confounding variables: uncontrolled variables that represent potential error in research (alternative explanations for results) aka extraneous variables Difference btn experimental and control groups other than independent variable Operational definition: term defined by how it is measured in research How would you defineintelligence? dancing? happiness? aggression? etc. Diagnostic criteria for Major Depression

Introduction Imp. terms (contd) Validity and reliability Validity = how accurate are results (true) Reliability = how consistent are results (consistencywould you get them again) Test-retest (similar results from same test) Parallel forms (do alternate versions agree) Inter-rater (do diff judges/raters agree) Split-half (do items referencing same issue score similarly)

NEW SUBTOPIC: OTHER ISSUES IN RESEARCH Modules 2 and 3: Research Methods

New major subtopic: Other issues in Research Within this topic, we will discuss Research settings and their advantages and disadvantages Types of measurements used in research

Other issues Research Settings: where research occurs Laboratory research: Controlled setting, unnatural People would not normally be there engaging in beh that study is examining Advantages Offers more control of extraneous variables Can standardize procedures Disadvantages Artificial May elicit atypical beh

Other issues (contd) Research settings (contd) Field research: Naturally occurring setting; Ss already there engaging in beh Advantages Offers more realistic view of beh in natural settings Disadvantages Less control of extraneous variables Less able to standardize procedures

Other issues (contd) Research measurements: how data is quantified Self-reports Ind reports on past beh, thoughts, beliefs, etc. Obtained through interviews, questionnaires, etc. Advantages: able to study what you cannot directly observe Disadvantages: Distortion of responses (people lie) Ability to be accurate can be limited (defense mechanisms, recall problems, diff perspectives)

Other issues (contd) Research measurements (contd) Behavioral observations Any activity that can be observed Examples raising hand, blood pressure, etc. Advantage Beh objectively measured Disadvantage Inds may act differently when observed

Other issues (contd) Research measurements (contd) Archival Records Data that already exists (collected by someone other than researcher) data would exist if study did not occur Examples medical records, crime rates, newspaper stories, etc. Advantage Observation does not influence data Disadvantage Incomplete records Not enough detail

Other issues (contd) Research measurements applied Counting the number of cigarette butts on the ground in a smoking area. Subjects rate their level of anger on scale of 1 10 Reviewing correlation between GPA and SAT over the last 20 years Counting the number of times a student leaves his seat Scores on test used to see if teaching method works

NEW SUBTOPIC: RESEARCH DESIGNS Modules 2 and 3: Research Methods

New major subtopic: Research Designs Introduction Research design How study is set up Influences procedures and conclusionswhat can you say about what you are studying when you get the results Describe Explain Predict Control Four types Descriptive research (case study, survey research, and naturalistic observation) Correlational research Experimental research Literature review (your term paper)

Research Designs (contd) Descriptive Case Study: In-depth examination of one ind (or few) Incl. use of interviews, observations, letters, diaries, reports from others, etc. Uses Source of insight/ideas (Piaget, Freud) Describe rare cases (Dissociative Identity D/O) Psychobiography (Eriksons Young Man Luther) Used to illustrate anecdotes

Research Designs (contd) Descriptive (contd) Case Study (contd) Advantage Able to study rare cases Initial exploration of new cases Disadvantages Not as systematicless control No comparison

Research Designs (contd) Descriptive (contd) Survey research Interview or questionnaire to lg grp of people Attempt to estimate attitudes or behs of lg grp Examples political polls, epidemiology studies Not simply because a survey is used No manipulation of variables Advantages Easy to do Lg amt of data quickly

Research Designs (contd) Descriptive (contd) Survey research (contd) Disadvantages People do not respond (either some items or completely) Effect of wording Ss may not know meaning of words Ss may give answers acceptable rather than accurate Questions may be poorly written Ss more likely to agree to not allowing versus forbidding

Research Designs (contd) Descriptive (contd) Survey research (contd) Disadvantages (contd) Effect of wording (contd) Actual wording influences When asked about assisting poor 23 % of Ss said too much money was spent, BUT when asked about welfare 52% said too much spent Order of questions People should have freedom to express their opinions publicly. Different responses depending on whether prior question dealt with Catholic Church or Nazi Party.

Research Designs (contd) Descriptive (contd) Naturalistic-observation Observe beh as it occurs in natural settings Jane Goodall and gorillas Advantage Able to see beh as it happens Disadvantage Decreased control over conditions

Research Designs (contd) Correlational research design Research that attempts to find links or connections btn vars so that if you know one var you can predict other Attempt to find rels btn variables How? Collect 2/more scores from ea S Examples TV violence and aggression College grades and salary

Research Designs (contd) Correlational research (contd) Correlation results Positive correlation = variables increase or decrease together (TV violence and aggression) Negative correlation = increase in one variable assoc with decrease in other (optimism & illness) Caution Correlation btn psych vars rarely perfect Correlation does NOT equal causation Can only say vars are related Cannot say causation may be third variable Illusory correlation: when connection appears to exist, but is actually random (when we believe rel exists, we tend to notice instances that confirm that belief)

Research Designs (contd) Experimental research design Research in which 1/more vars is manipulated (controlled by researcher) to see if it causes changes in another var To est cause and effect relationships btn variables

Research Designs (contd) Experimental research (contd) Variables in experimental research Independent variable (IV): variable that is manipulated/controlled by researcher Dependent variable (DV): variable that is affected by IV Examples effect of ____ (IV) on ____ (DV) Increases in anxiety cause improvement in performance Observing live models perform aggressive acts led to those children engaging in aggressive acts

Research Designs (contd) Experimental research (contd) Two groups of subjects Experimental group: grp that gets IV Control group: does not get IV Both groups measured on DV Important only diff btn grps should be IV (random sampling and random assignment) This is what allows you to say the IV causes a change in DV (i.e., make cause and effect conclusions) Why?

Research Designs (contd) Experimental research (contd) Essential features of this design Comparison of at least 2 groups (control and experimental grp) Manipulation of IV by researcher Random assignment of Ss to groups Summary want to see if there is diff in scores btn grps so you can say it was IV that caused diff (everything else same => only diff is IV)

Research Designs (contd) Literature review Summary of broad range of research on subject Most published research studies have literature review within introductionsupports direction of study and eventual hypothesis Term paper for this class

Comparing Research Methods Research Method Basic PurposeHow Conducted What is Manipulated Weaknesses Summary of the types of Research DescriptiveTo observe and record behavior Perform case studies, surveys, or naturalistic observations NothingNo control of variables; single cases may be misleading CorrelationalTo detect naturally occurring relationships; to assess how well one variable predicts another Compute statistical association, sometimes among survey responses NothingDoes not specify cause-effect; one variable predicts another but this does not mean one causes the other ExperimentalTo explore cause- effect Manipulate one or more factors; randomly assign some to control group The independent variable(s) Sometimes not possible for practical or ethical reasons; results may not generalize to other contexts

NEW SUBTOPIC: VALIDITY Modules 2 and 3: Research Methods

New major subtopic: Validity Validity: degree to which correct inferences or conclusions can be made (i.e., how true) External validity: extent to which results can be generalized to population Ensure sample is representative of pop Random sampling is best Want to know that sample is like pop

Validity (contd) Internal validity: extent to which diffs in DV are due to diffs in IV and not some other confounding variable What do psychists hope to achieve in experiment? Results are due to IV and not something else When it is not the IV and is something else Threats to internal validity of study Subject characteristics There are diffs btn exper. and control grps that could cause diffs in DV (instead of IV) Problem in selection and assignment of Ss Grps differ in unintended ways

ValidityThreats (contd) Mortality Parts of full results missing incomplete data Ind drops out of study or does not answer all ?s Limits ability to generalize are Ss who dropped out systematically diff from those who stay in study (Hites women and sexuality study) Location Where study occurs influences results Situation-relevant confounding variable: situations in which groups are placed should be equivalent.

ValidityThreats (contd) Instrumentation Ways measurements or procedures were done are inaccurate Examples Is method of measurement accurate? (flawed test) Does person collecting data interfere with accuracy? (presence of observer) Does bias of collector influence data? (seeing results as you would want them) Solutions Double-blind procedure: neither participants nor researcher knows who is in what group

ValidityThreats (contd) Testing Experience of taking pretest affects performance on posttest Control grp helps to prevent this History Something occurs during course of experiment that affected results More likely in longitudinal studies (longer period of time)

ValidityThreats (contd) Maturation Changes in DV may be influenced in development that occurs in Ss over time Usually with longitudinal studies Attitude of Ss Subjects view of participation in study influences results Two examples Hawthorne effect: Ss knowledge or feeling special causes positive results Placebo effect: respond b/c belief that med will work

ValidityThreats (contd) Regression threat Results are due to statistical regression toward average Statistical phenomenon more likely to occur with extreme scores Minimizing threats Standardize conditions Obtain more info on Ss Obtain more info on details of study Use appropriate design

NEW SUBTOPIC: ETHICS IN RESEARCH Modules 2 and 3: Research Methods

New major subtopic: Ethics in research Ethical guidelines in psychological research Major consideration = DO NO HARM How is this assured? Informed consent Confidentiality of data and results Minimize potential for harm in procedures Debrief after study

NEW SUBTOPIC: STATISTICS Modules 2 and 3: Research Methods

New major subtopic: Statistics Statistics used in research for two major reasons Describing data organize it in meaningful way Making inferences how confidently can we infer that observed difference (results) accurately estimate true difference

StatisticsDescribing Data Descriptive statistics: provide info about distribution of scores Frequency distribution: how frequently ea score occurs N = number of scores

Statistics: Descriptive Statistics (contd) Measures of central tendency: attempt to describe grp of scores / single score that represents set of scores Mean = mathematical average (sensitive to extreme scores) Median = score at which 50% of scores fall above and 50% fall below Mode = most frequently occurring score

Statistics: Descriptive Statistics (contd) Measures of variability: measure of how much scores are spread out among distribution (how similar or diverse scores are) Range: diff btn highest and lowest score Standard deviation: how scores vary around mean / ave distance of ea score from mean Used in many other inferential stats Averages of data with lower variability more reliable than averages of data with high variablity

Statistics: Descriptive Statistics (contd) Standard deviation (same mean diff variability)

Statistics: Descriptive Statistics (contd) Normal distribution: distribution of scores where mean, median, and mode are all same score All variables are assumed to distribute themselves along normal dist. Percentiles: indicate % of scores that fall below particular score AKA normal curve, bell curve Skewed distribution: when distribution is not normally distributed

Statistics: Descriptive Statistics (contd)

Skewed vs. Normal Distribution Income distribution is skewed by the very rich. Intelligence test distribution tends to form a symmetric bell shape that is so typical that it is called the normal curve. Skewed distribution Normal curve

Statistics: Descriptive Statistics (contd) Correlation Coefficient: indicates strength and direction of rel btn two variables Score btn + or 1.0 Strength = how close number is to 1.0 Direction = + or Positive correlation => both variables increase or decrease together Negative correlation => when one increases, other decreases

Correlation Coefficient The correlation coefficient is a number representing the strength and direction of correlation. The strength of the relationship refers to how close the dots are to a straight line, which means one variable changes exactly as the other one does; this number varies from 0.00 to +/- 1.00. The direction of the correlation can be positive (both variables increase together) or negative (as one goes up, the other goes down). + 1.00 - 1.00 0.00 Perfect positive correlation Perfect negative correlation No relationship, no correlation Guess the Correlation Coefficients

Statistics: Descriptive Statistics (contd) Correlation coefficient example

When scatterplots reveal correlations: Height relates to shoe size, but does it also correlate to temperamental reactivity score? A table doesnt show this, but the scatterplot does.

Correlation is not Causation! People who floss more regularly have less risk of heart disease. If these data are from a survey, can we conclude that flossing might prevent heart disease? Or that people with heart- healthy habits also floss regularly?

Thinking critically: If a low self-esteem test score predicts a high depression score, what have we confirmed? that low self-esteem causes or worsens depression? that depression is bad for self-esteem? that low self-esteem may be part of the definition of depression, and that were not really connecting two different variables at all?

If self-esteem correlates with depression, there are still numerous possible causal links:

Statistics: Inferential Statistics (new subtopic) Inferential statistics: allow researcher to draw conclusions from sample to pop / whether diffs btn groups are meaningful If means of groups from sample reliable, then differences are more likely reliable. Why used? Is diff in DV btn control and exper. grp large enough to mean something? Is diff in DV due to chance or IV? When is observed difference considered more reliable? Representative sample (not extreme/unusual cases) Lower variability (versus > spread out) Greater number of subjects

Statistics: Inferential Statistics (contd) Examples t-test: when two variables are studied ANOVA: > two variables Statistical significance: measure of probability that results (diffs btn experimental and control) were due to chance and not IV Sample averages reliable and when difference btn them is large, then diff is statistically significant What is chance that difference btn groups is due to chance? Read as likelihood results were due to chance Expressed in reports as (p

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RESEARCH METHODS Modules 2 and 3. Class Experiment This is a study of some factors that may affect the solution of anagrams or scrambled words. A list