Technique for developing measurement tools What is measurement

Technique for developing measurement tools

What is measurement? • process of assigning numbers to the object or observations,

introduction • Physical features of the objects we measure • E. g. height…weight • It is a demanding and a complex task • Some aspects easy to assign numbers and some very difficult • E. g. marital adjustment, intelligence are difficult to measure by giving numbers

Techniques for development • Four stages • 1. concept development • 2. specification of dimensions • 3. selection of indicators • 4. formation of index

1. Concept development For which the investigator must understand what he want to study. Can take theoretical base to develop the concepts

2. • Develop dimensions for the concepts • That helps in deduction • Intuitive approach • E. g image of nursing profession if you want to study then you may think about dimension such as sense of social status, status within the health profession, autonomy of the profession, patient concerns sense of social responsibility…

3. indicators • Think how you are going to measure the each dimension • How I can score • Will there be possible to measure the dimension with more than one indicators • If possible to measure with more than one indicators. It gives more stability and also improves the validity.

4. Formation of index • Decide overall index to measure the entire scale • where you will be able to measure all dimension using one single index.

Scale construction approaches • Arbitrary approach: adhoc base the scale is developed • Widely used approach • Here assumed that the scale would measure the concept for which it has been designed • Although there is no or little support /evidence to accept such assumption

Consensus approach • Here panel of judges will evaluate the items • They evaluate for the relevancy, unambiguous implication

Item analysis approach • Discriminate index is calculated with high total scores and low scores

Cumulative scale • Chosen on the basis of some ranking of items with ascending or descending discriminating power

Factor scales • Constructed based on inter-correlations of items • Indicates a common factor accounts for the relationship between the items