CHAPTER 12

Personality Assessment: An Overview

Personality and Personality Assessment Defined

• Traits, Types, and States– Personality states : What I do in a particular

situation (I am angry because he insults me when I lost my financial aids)

– Personality traits: This trait is one of my attributes or characters (bad-tempered, impatience )

– Personality types: this is what you are!!!! This defines you (e.g. You are a psychopath; you will rape and kill people no matter what. You are Type A, you are always nervous)

Personality state and Situational factors

• Milgram study

• Zimbardo prison experiment

• How could many Germans who were Christians support the Nazi party during WWII?

• Why did many Chinese people persecute their parents during the Cultural Revolution in Communist China?

Personality state and Situational factors

• Sonmez, S.; Apostolopoulos, Y; Yu, C. H.; Mattila, A., & Yu, L. C. (2006). Binge drinking and casual sex on spring break. Annals of Tourism Research, 33, 895-917.

• People will do unusual things in unusual situations

Another drawback: Vagueness

• You have a great need for other people to like and admire you. You have a tendency to be critical of yourself. You have a great deal of unused capacity which you have not turned to your advantage. While you have some personality weaknesses, you are generally able to compensate for them. Your sexual adjustment has presented problems for you. Disciplined and self-controlled outside, you tend to be worrisome and insecure inside.

Another drawback: Vagueness

• At times you have serious doubts as to whether you have made the right decision or done the right thing. You prefer a certain amount of change and variety and become dissatisfied when hemmed in by restrictions and limitations. You pride yourself as an independent thinker and do not accept others’ statements without satisfactory proof. You have found it unwise to be too frank in revealing yourself to others. At times you are extroverted, affable, sociable, while at other times you are introverted, wary, reserved. Some of your aspirations tend to be pretty unrealistic. Security is one of your major goals in life.

Myers-Briggs Type Indicator

• http://www.humanmetrics.com/cgi-win/jtypes2.asp

Big Five

• Convergent validity (Chapter 6)

• Discriminant validity (Chapter 6)

Why Big Five?Personality and

relationship

• Solomon and Robertson: If a couple is incompatible in Big Five, the probability of divorce is very high. If you have a boy friend or girl friend, please consider taking the Big Five assessment with him/her together.

• Solomon, B. C., & Jackson, J. J. (2014). Why do personality traits predict divorce? Multiple pathways through satisfaction. Journal of Personality and Social Psychology, 106(6), 978-996. doi:10.1037/a0036190  

Some Basic Questions

• Who?– The self as the primary referent– Another person as the referent– The cultural background of assessees• Reliability of self-report data (Cook and Campbell 1979)– People tend to report what they believe the researcher

expects to see– People report what reflects positively on their own

abilities, knowledge, beliefs, or opinions.

Paradox of Self-report

• Paradox of self-attribution• “I am very humble and I am proud of

it!”• “Moses was a very humble man,

more humble than anyone else on the face of the earth.” (Numbers 12:3)

• “I am not violent! Don’t insult me or I will kill you!”

• We need rating of another person!

Tools of Test Development

• Data Reduction Methods• PCA (Chapter 6)• Factor analysis (Chapter 6)• Cluster analysis

Cluster analysis• Example-based vs. rule-based• Three types:

– Two-step clustering– K-mean clustering– Hierarchical clustering

• Warning: If there are too many missing data, no clustering algorithm can yield good results.

K-mean • In a two-dimensional data set (X and Y only), you can “eye-

ball” the graph to assign clusters. But it may be subjective. • When there are more than two dimensions, assigning by

looking is almost impossible.

K-mean

• Select K points as the initial centroids

• Assign points to different centroids based upon the P matrix (proximity)

• Re-evaluate the centroid of each group

• Repeat Step 2 and 3 until the best solution emerges (the centers are stable)

Two-step clustering (concept only)

• The ultimate dimension reduction technique

• K-mean accepts continuous data only but 2-step can accept both categorical and continuous.

• You need to pre-specify the number of clusters in K-mean. In 2-step the algorithm suggests the number of clusters for you (data-driven).

• 2 steps: precluster, clustering

Example of two-step clustering

• Schwartz value survey (SVS)

• 57 items• Factor analysis

reduces 57 items to 10 dimensions (subscales).

• Group 10 into 4.

Two Distinct Groups• Compared to Christians in Cluster 1, Christians in

Cluster 2 are – Higher on personal focus values, such as self-direction,

stimulation, and hedonism, achievement, and power

– Lower on social focus values, such as conformity, tradition, benevolence, and universalism. Security is considered self-focused

• Cluster 1: Personal-focused Christians• Cluster 2: Social-focused Christians

Hierarchical clustering

– grouping/matching people like what e-harmony and Christian-Mingle do. Who is the best match? Who is the second best? The third…etc.

Hierarchical clustering

• Top-down or Divisive: start with one group and then partition the data step by step according to the matrices

• Bottom-up or Agglomerative: start with one single piece of datum and then merge it with others to form larger groups