Abstract
I have generally used the terms assessment and measurement interchangeably, but assembling the articles for this issue of the Journal of Applied Gerontology led me to delve into these concepts a bit further. Much of my scientific dissemination related to measurement has focused on concepts such as reliability and validity. However, as I have collaborated more extensively with community partners in applied settings, the term assessment is favored and measurement is usually not even mentioned. But are measurement and assessment one and the same? To this end, I consulted a source in educational psychology and found the following: “Assessment refers to the collection of data to describe or better understand an issue,” while “measurement is the process of quantifying assessment data” (Huitt, Hummel, & Kaeck, 2001). Although assessment itself has various meanings across disciplines (e.g., health assessment, nursing assessment, etc.), I felt Huitt and colleagues’ definitions were useful in differentiating the two concepts.
Assessment and measurement are linked (I would argue you cannot do one well if you do not do the other well), and the articles in this issue of the Journal of Applied Gerontology both adapt and test classic measures as well as examine critical assessment strategies. For example, the study by Smale, McIntosh, and Vallis (2016) compared two methods to assess fat free mass index in older adults. Both methods (bioelectrical impedance analysis [BIA] and air displacement plethysmography [ADP]) suggested these two approaches agreed significantly, but concordance lessened when the sample was split by gender. This useful analysis offers the clinical recommendation that portable devices such as BIA should be administered with caution among older adults.
The next set of articles in this issue provides fresh perspectives on several widely used measures. Branger, O’Connell, and Morgan (2016) conducted a factor analysis of the 12-item version of the Zarit Burden Interview (ZBI), the most commonly used measures of family caregiver distress. Utilizing a sample of rural and urban caregivers of individuals with dementia, Branger and colleagues confirmed a two-factor structure of the ZBI (personal strain and role strain) as well as factorial invariance across subgroups. Only personal strain appeared empirically associated with caregivers’ psychological distress, suggesting the potential clinical importance of this sub-dimension of caregiver burden. Similarly, Gray, Kim, Ciesla, and Yao (2016) examined whether the six-item version of the widely used Lubben Social Network Scale (LSNS-6) demonstrated strong psychometric properties when measuring social networks of older adults. In an intriguing application of Rasch analysis in addition to principal components analysis, the authors found that collapsing the response categories of the LSNS-6 from six to four and the inclusion of items that measure less and more developed social networks could improve the psychometrics of the LSNS-6 even further. Such steps could enhance the assessment capability of this highly useful measure. In another interesting analysis of an established measure, Ng, Quinn, Burcu, and Harrington (2016) examined the unidimensional properties of an expanded, pooled measure of function that combines classic activities of daily living and instrumental activities of daily living. Relying on a large sample of older adults with diabetes drawn from the 2009 Medicare Current Beneficiary Survey, Ng et al. suggest that a combined functional scale operates well as a single dimension following a comprehensive analysis of factor structure. Such results raise questions about whether basic and instrumental activities of daily living operate more appropriately as separate constructs (which is how they are traditionally applied in geriatric and gerontological research) or as a single construct.
Menec and colleagues conclude this issue with a comparison of residents’ and municipal officials’ assessment of age-friendliness of largely rural communities in Manitoba, Canada. Overall, the extent of agreement between officials’ and residents’ assessments of communities’ age-friendly features (e.g., appropriate transportation, housing availability, etc.) was high, although municipal officials’ ratings were on average higher than those of residents. In addition to emphasizing the importance of multiple stakeholder viewpoints when assessing age-friendliness of communities, Menec, Newall, and Nowicki (2016) suggest the need to further explore the reasons why there is a disconnect between residents and officials when striving for the crucial goal of age-friendliness in our communities.
Quality measurement and assessment go hand in hand, and the articles in this issue of the Journal of Applied Gerontology help to advance such efforts. In many of my community partnerships, there is often tension between the need for brief, easy-to-administer items and the inclusion of measures that are of the highest quality. Via empirical comparisons of approaches as well as revisiting the psychometric properties of widely used tools, the studies in this issue help to bridge such gaps to result in useful, practical assessment approaches that feature rigorous measurement.