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 Questions That Will be Answered in Today’s Lecture 6. What types of measures are used to assess personality? 7. How are the reliability and validity of personality measures assessed?

Psychology 3054 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 3055 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 for a given personality characteristic involves counting the number of statements that refer to that characteristic.

Psychology 3056 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 3057 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 3058 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 3059 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.  Collectivists tend to score slightly lower than individualists.

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  Multiple informants can be used to assess a single participant, thereby reducing the impact of any biases in the observations of a single individual. 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 and emphasize the positive attributes of her child).

Psychology Personality Measures that Rely Upon Behavioural Data (B-Data) Data may be collected in either natural settings 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, muscle contraction). 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 one of 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 one of 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 (i.e., the stability of participants’ scores across time). 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., The items from Rosenberg’s Self-Esteem Scale appear to have face validity. All in all, I am inclined to feel that I am a failure On the whole, I am satisfied with myself

Psychology Content validity: Refers to the degree to which a measure assesses the underlying dimensions of the construct under study. E.g., Self-esteem Rosenberg’s Self-Esteem Scale: Assumes self-esteem is unidimensional. Harter’s Self-Perception Profile: Assumes self- esteem is multidimensional; assesses self- esteem related to scholastic competence, athletic competence, social acceptance, physical appearance and behavioural conduct.

Psychology Content validity is assessed in one of two ways: (a) By having experts judge the adequacy with which the measure assesses the underlying dimensions of the construct. (b)In the case of questionnaire measures, factor analyzing participants’ responses to the items. Factor analysis is a statistical procedure that identifies items that are highly correlated with one another; each group of highly correlated items is thought to reflect a single dimension of the construct under study.

Psychology Predictive validity (or criterion validity): Refers to the degree to which a measure is able to predict the likelihood or extremity of a behaviour (i.e., a criterion) that is theoretically related to the construct under study. E.g., A self-esteem measure that is high in predictive validity should be able to predict:  alcohol and drug use  persistence in the face of failure  number of sexual partners (i.e., sexual promiscuity)

Psychology Questions That Were Answered in Today’s Lecture 6. What types of measures are used to assess personality? 7. How are the reliability and validity of personality measures assessed?