Psychology 3051 Psychology 305: Theories of Personality Lecture 2

Psychology 3052 Scoring your questionnaire: 1. Reverse score items 3, 5, 8, 9, and  1 4  2 3 = 3 2  4 1  5 2. Sum scores across 10 items.

Psychology 3053 Lecture 2 1. How is research used to test theories? (continued) 2. What types of measures are used to assess personality? 3. How are the reliability and validity of personality measures assessed? Research Methods

By the end of today’s class, you should be able to: 1. compare and contrast experiments, correlational studies, quasi-experimental studies, and case studies. 2. apply research methods to distinct hypotheses. 3. distinguish between S-, I-, and B-data. 4. identify the advantages and disadvantages of S-, I-, and B-data. 4

6. distinguish between internal consistency, inter-rater reliability, and test-retest reliability. 7. define face validity describe classical test theory.

6 4. Case Studies  Involve the in-depth examination of the life of one person.  Assessment techniques include: Observation Interviews Administration of standard personality tests Analysis of written text How is Research Used to Test Theories? (continued)

7 Ted Bundy,

8 Exercise: Application of Research Methods Construct: Happiness. Possible operationalizations: Measure of life satisfaction. Measure assessing the frequency and intensity with which participants experience positive emotions (e.g., joy, contentment, excitement). Number of times participants smile.

9 People experience happiness when they have successfully influenced others’ opinions. Experimental study. Hypothesis Ideal Research Method

10 Group A Group B Random Assignment Treatment A Posttest A Simple Experiment Treatment B Posttest Pretest

11 People experience happiness when they have successfully influenced others’ opinions. People who report extraordinarily high levels of happiness exhibit a unique constellation of personality characteristics. People who experience high levels of happiness tend to be more optimistic. Experimental study. Case study. Correlational study or quasi-experimental study. Hypothesis Ideal Research Method

Psychology What types of measures are used to assess personality? There are three types of personality measures. 1. Personality Measures that Rely Upon Self-Report Data (S-Data) Most common method used for measuring personality. Data are provided by the participant. Data are collected through interviews or questionnaires; questionnaires are most commonly used.

Psychology Unstructured questionnaires require participants to complete open-ended fill-in-the-blank items. There are 2 types of questionnaires: Unstructured and structured. E.g. Twenty Statements Test: Participants complete the statement “I am” 20 times. Coding involves counting the number of statements that refer to a given characteristic.

Psychology Structured questionnaires require participants to complete items with limited response options. E.g.,True/false items: I like loud and crowded parties ………… T/F I enjoy trying new foods …………………. T/F E.g.,Adjective checklists: adventurous conservative E.g., Adjectives or statements accompanied by rating scales:

Psychology Using the scale below, indicate how descriptive you believe each of the following traits is of you. Circle the appropriate number to the right of each trait Not at allSomewhatHighly descriptivedescriptivedescriptive 1. Adventurous Ambitious Broad-minded Conservative Extroverted12345

Psychology Using the scale below, please indicate how much you disagree or agree with the following statements. Circle the appropriate number to the right of each statement StronglyNeutralStrongly disagree agree 1. I feel that I’m a person of worth, at least on an equal basis with others …………………………… I feel that I have a number of good qualities …… All in all, I am inclined to feel that I am a failure … I am able to do things as well as most people ……12

Psychology Rosenberg’s Self-Esteem Scale  Score by reversing “negatively-keyed” items and summing responses to 10 items.  Measures global feelings of self-worth.  Mean score for university undergraduates: 38, SD = 6.2.  Females tend to score slightly lower than males.

Psychology  The participant can report on his/her private experiences (e.g., emotions, desires, beliefs). Advantages of S-Data:  Inexpensive.  The participant can report on his/her personality across diverse contexts; allows for general characteristics to be assessed.

Psychology  The participant’s responses may be biased (e.g., the participant may exaggerate positive attributes and/or minimize negative attributes). Disadvantages of S-Data:  The participant may lack sufficient self-insight to accurately respond to the items.

Psychology Personality Measures that Rely Upon Informant Data (I-Data) Typically, informants are asked to complete structured questionnaires similar to those described for S-Data. Data are provided by individuals who are well acquainted with the participant.

Psychology Advantages of I-Data:  Informants can report on characteristics that the participant may be unaware of (e.g., social reputation).  Informants’ judgments provide an assessment of the participant’s characteristics in natural settings.

Psychology  Informants’ judgments are often limited to specific contexts and, therefore, do not allow for the participant’s general characteristics to be assessed. Disadvantages of I-Data:  Informants are unaware of many of the participant’s private experiences (e.g., emotions, desires, beliefs).  Informants’ judgments may be biased (e.g., a mother may overlook the negative attributes of her child).

Psychology Personality Measures that Rely Upon Behavioural Data (B-Data) Data may be collected in either natural or laboratory settings. Data are collected through the researcher’s direct observation of the participant.

Psychology Advantages of B-data collected in natural settings: (a) Natural settings:  The observations provide an assessment of the participant’s characteristics in naturally-occurring situations. The researcher observes the participant engage in his/her daily activities (e.g., observes the participant at home, has the participant complete a daily diary).  The data are not subject to the biases inherent in S-data and I-data.

Psychology Disadvantages of B-data collected in natural settings:  Events that the researcher wishes to observe may not occur.  Costly.  The presence of the researcher may influence the participant’s behaviour.

Psychology The researcher observes the participant in the laboratory. (b) Laboratory settings: Three types of B-data are collected in the laboratory: 1. The participant’s overt behavioural reactions. 2.The participant’s covert physiological reactions (e.g., heart rate, galvanic skin response). 3. The participant’s responses to projective tests (e.g., Rorschach Ink Blot Test).

Psychology Example of the Rorschach Ink Blot Test:

Psychology Advantages of B-data collected in laboratory settings:  The data are not subject to the biases inherent in S- data and I-data.  Allows the researcher to control extraneous influences on the participant’s behaviour.  Allows the researcher to observe the participant’s reactions to events that are not likely to occur in natural settings.

Psychology Disadvantages of B-data collected in laboratory settings:  The results are difficult to generalize to naturally- occurring situations.  The presence of the researcher may influence the participant’s behaviour.

Psychology How are the reliability and validity of personality In order to accurately assess a given personality characteristic, the measure that is used (whether it is based on S-, I-, or B-data) must be both reliable and valid.  Refers to the consistency with which a measure assesses a given construct across repeated measurements. Reliability measures assessed?

Psychology  Method for increasing the reliability of a measure: Theoretically, the error associated with one assessment should cancel out the error associated with another assessment. Include multiple assessments of the construct of interest within the measure.

Psychology  Thus, for measures that rely upon (a) S-data: Include more than one item. (b) I-data:Include more than one item and/or use more than one informant. (c) B-data: Make more than one observation and/or use more than one observer.

Psychology I like to work alone rather than in groups. 2.I keep a schedule every day. 3.I tend to seek out leadership roles. 4.I never leave a task unfinished. 5.I’m a bad loser. 6.Hard work pays off in the long run. 7.I feel my best is never good enough. 8.I have high expectations for myself. 9.I continually strive for excellence. 10. It’s important for me to know I’m doing my best.

Psychology  The reliability of a measure is assessed in three ways. 1.Internal consistency: Relevant for multi-item questionnaires (S- or I-data). Reflects the degree to which the items that comprise the questionnaire are consistent with one another (i.e., tap the same underlying construct).

Psychology (b) Cronbach’s alpha reliability coefficient: Involves calculating the correlation between each pair of items and averaging the resulting correlations; most common method for assessing internal consistency; acceptable alpha for a questionnaire >.75. The internal consistency of a questionnaire is assessed in two ways: (a) Split-half reliability coefficient: Involves splitting the items in half and calculating the correlation between participants’ scores on the two halves.

Psychology Inter-rater reliability: Relevant for studies in which two or more individuals rate the participant on a given characteristic or behaviour (S-, I-, or B-data). In the case of S-data, the raters are coders scoring participants’ responses to interviews or unstructured questionnaires; in the case of I-data, the raters are informants; in the case of B-data, the raters are researchers.

Psychology Reflects the degree to which the scores provided by different raters are consistent with one another (i.e., the degree to which there is consensus among the raters). Involves calculating the correlations between the scores provided by different raters.

Psychology Test-retest reliability: Relevant for all types of measures (S-, I-, or B-data). Reflects the degree to which the scores participants obtained in one test administration are consistent with the scores they obtained in a second test administration. Involves calculating the correlation between the scores participants obtained in the first test administration and the scores they obtained in the second test administration.

Psychology  Refers to the degree to which a measure assesses the construct it is intended to measure. Validity (or Construct Validity)  A measure that is reliable may or may not be valid; a reliable measure may bear no relationship to the construct it was intended to measure.

Psychology  The validity of a measure may be established by demonstrating that it possesses one or more of the following forms of validity. 1. Face validity: Refers to the degree to which a measure appears to tap the construct under study. E.g., Rosenberg’s Self-Esteem Scale. All in all, I am inclined to feel that I am a failure On the whole, I am satisfied with myself

Psychology Lecture 2 1. How is research used to test theories? (continued) 2. What types of measures are used to assess personality? 3. How are the reliability and validity of personality measures assessed? Research Methods