Examining the construct validity of the Basic Traits Inventory and the Ten-Item Personality Inventory in the South African context

Page 1 of 9 Original Research Examining the construct validity of the Basic Traits Inventory and the Ten-Item Personality Inventory in the South African context Authors: Samantha A. Metzer1 Gideon P. de Bruin1 Byron G. Adams1 Affiliations: 1 Department of Industrial Psychology and People Management, University of Johannesburg, South Africa Correspondence to: Byron Adams Email: Postal address: PO Box 524, Auckland Park 2006, South Africa Dates: Received: 25 July 2011 Accepted: 01 Feb. 2014 Published: 27 Aug. 2014 How to cite this articl: Metzer, S.A., De Bruin, G.P., & Adams, B.G. (2014). Examining the construct validity of the Basic Traits Inventory and the Ten-Item Personality Inventory in the South African context. SA Journal of Industrial Psychology/SA Tydskrif vir Bedryfsielkunde, 40(1), Art. #1005, 9 pages. http:// dx.doi.org/10.4102/sajip. v40i1.1005 Copyright: © 2014. The Authors. Licensee: AOSIS OpenJournals. This work is licensed under the Creative Commons Attribution License. Orientation: As there has recently been a need for researchers to consider shorter personality measures, we compared the construct validity of a longer and a shorter personality measure in the South African context. Research purpose: The main purpose of this study was to examine the discriminant and convergent validity of two personality measures that measure the big five personality factors: the longer Basic Traits Inventory (BTI) and the shorter Ten-Item Personality Inventory (TIPI). Motivation for the study: Researchers have indicated a need for shorter personality measures, such as the TIPI, to assess personality dimensions. This study assessed the validity of the shorter measure in comparison with the BTI, which is considered cross-culturally valid in the South African context. Research approach, design and method: This study used a quantitative research design. Both personality measures were administered manually to a convenience sample of student participants (n = 662), and data were analysed through factor analysis utilising oblique rotation for all items. Main findings: The main findings indicate that, although the construct validity of both measures was satisfactory, the TIPI yielded unsatisfactory reliability. Practical/managerial implications: The BTI is a more reliable measure than the TIPI, which should only be used when time is limited. Contribution/value-add: In addition to providing insight into how the length of an assessment impacts on the reliability of a measure, this study further reinforces the use of the basic traits inventory as a measure that reliably measures personality in South Africa. Introduction Personality measures are considered important for making decisions regarding individuals. They are used to understand why humans behave and think as they do by identifying the unique set of traits, characteristics or attitudes of a person, understanding a person’s performance potential and possibly their career interest (Costa, 2008; Salkind, 2006; Tett & Burnett, 2003). In this study we examine how the length of a personality measure impacts on the measure’s construct validity. Most personality measures are often considered long, and, particularly in research settings (Gosling, Rentfrow, & Swann, 2003), candidates may experience fatigue, frustration and confusion (Saucier, 1994) whilst completing them. In South Africa, in addition to the fatigue, frustration and confusion candidates may face, there is also the question of the diverse South African population (Meiring, Van de Vijver, Rothmann & Barrick, 2005). Here there are considerations of culture, language and socio-economic status which may impact individuals’ responses and that may result in candidates not answering questions accurately or the inaccurate interpretation of individual results. Therefore, the impact of the length of a measure may provide additional insight into the psychometric properties of personality measures in South Africa. In South Africa, the use of psychological assessment is governed by the Employment Equity Act (Act No. 55 of 1998), which states that: Read online: Scan this QR code with your smart phone or mobile device to read online. psychological testing and other similar assessments are prohibited unless the test or assessment being used (a) has been scientifically shown to be valid and reliable, (b) can be applied fairly to all employees, and (c) is not biased against any employee or group. (Republic of South Africa, 1998, p. 9) The onus is therefore on the psychologist to acquire and utilise knowledge that will allow them to develop shorter personality measures from which more rapid decisions can be made http://www.sajip.co.za doi:10.4102/sajip.v40i1.1005 Page 2 of 9 in comparison with longer personality questionnaires (Van Eeden, Cilliers & Van Deventer, 2008). However, irrespective of its length, a personality measure requires a demonstration of satisfactory psychometric properties in line with South African legislation (Meiring et al., 2005). According to Friedenberg (1995), an effective test displays three important psychometric properties: firstly, the test is valid, secondly, the test is reliable and, thirdly, it contains items that have valid item statistics. It is widely accepted that long questionnaires have better psychometric properties than short questionnaires (Gosling et al., 2003). Most test administrators today would be very concerned if a test consisted of only a few items. A study by Burisch (1997) shows that the psychometric advantages of a long test is not always what one would expect. He compared subsets of two relatively short depression scales (nine and eight items respectively) with much longer ones (50 and 28 items respectively). The selected scale subsets were based on their content, and in 10 out of the 19 cases the selected subsets performed psychometrically better than the longer measures; in other words, curtailing scales enhanced rather than attenuated their validity. Burisch (1997) suggests that when a test is being developed, it is not necessarily the number of items included that is important, but rather the quality of the item definitions in measuring a specific construct. However, there are also several limitations of using shorter personality measures. In the study by Gosling et al. (2003) three limitations were identified. Firstly, there was a decrease in the reliability properties compared to longer questionnaires with standard multi-item measures. Secondly, the short questionnaire was less reliable, converged less strongly with the big five personality measure and had weaker correlations with other variables. Thirdly, the individual facets of multifaceted constructs are not always measured accurately, and therefore a longer personality questionnaire is preferable. The Five-Factor Trait Model The Five-Factor Trait Model (FFM) is currently the most popular model of personality trait factors and has served as a foundation for pe (...truncated)