TAPAS Forced-Choice Methodology

Question 1

What is the fundamental structure of a forced-choice item on TAPAS?

Accepted Answer

Two statements from different personality dimensions paired together, requiring a preference choice

Answer

Each TAPAS forced-choice item presents two statements from different personality dimensions, and the respondent must indicate which statement is more self-descriptive. This pairwise comparison format is the core of the forced-choice methodology. By comparing statements across dimensions rather than rating them independently, the format reduces several types of response bias.

Question 2

Why are the two statements in a TAPAS forced-choice pair matched on social desirability?

Accepted Answer

To prevent respondents from identifying and choosing the more socially acceptable option

Answer

Matching statements on social desirability ensures that both options in a pair are equally attractive or equally neutral. When both statements are equally socially desirable, respondents cannot simply choose the 'better sounding' option and must instead make a genuine preference judgment. This is a key anti-faking mechanism in the TAPAS forced-choice design.

Question 3

What psychometric model underlies the scoring of TAPAS forced-choice items?

Accepted Answer

The Thurstonian item response theory (IRT) model for forced-choice data

Answer

TAPAS uses a Thurstonian item response theory model specifically designed for forced-choice data. This model estimates the latent trait levels for each personality dimension while accounting for the comparative nature of forced-choice responses. Developed by researchers including Drasgow and colleagues, it overcomes the traditional limitations of ipsative scoring that plagued earlier forced-choice instruments.

Question 4

What is 'ipsative scoring' and why was it historically a problem for forced-choice personality measures?

Accepted Answer

Ipsative scoring produces within-person relative scores that cannot be meaningfully compared across individuals

Answer

Ipsative scoring occurs when forced-choice item scores are calculated such that each person's total across dimensions is constrained to be the same. This means scores only indicate relative strengths within a person, not absolute standing compared to others. For selection purposes, between-person comparisons are essential, making traditional ipsative scoring problematic for forced-choice instruments.

Question 5

How does TAPAS overcome the ipsative scoring problem that limited earlier forced-choice instruments?

Accepted Answer

By using the Thurstonian IRT model to estimate normative (between-person comparable) scores from forced-choice data

Answer

TAPAS overcomes the ipsative scoring limitation through the Thurstonian IRT model, which provides normative score estimates from forced-choice data. This statistical model separates the individual trait levels from the comparative format, producing scores that can be meaningfully compared across individuals. This breakthrough made forced-choice measurement viable for high-stakes selection contexts.

TAPAS - Tailored Adaptive Personality Assessment System Practice Test

TAPAS - Tailored Adaptive Personality Assessment System Practice Test

TAPAS Forced-Choice Methodology