Reliability and Validity

This week I would first like to address our class activity last week that was done in the computer lab.  The problems that were given are very familiar to me and actually bring about some excitement.  During both of my previous statistic classes, I loved all the parts that related to math and being able to perform calculations.  After my second class I was able to take it even a step further and could then use those numbers to interpret data and my results.  The more comfortable I become with this information the better I feel about doing research and using data as a school counselor.  In class when I was able to help my classmates with working Excel and successfully finishing all of the problems, I had a great sense of pride and accomplishment.  This was a very motivating feeling and something that I have been looking for this year in the program.  It also made me realize that if I had taken Appraisal before Guidance Program Development things may have fit together better for me.  However, I do have the advantage of understanding a greater picture the way I have completed the classes.  Appraisal fits into the overall picture I have already created and it seems to be filling some of the holes.  I am excited to see how much more confidence I can gain by the end of the semester and this class.

Both chapters for this week were again somewhat of a review from my previous classes, however it took a new approach that I was not as familiar with.  In the Reliability chapter, the sources of measurement error were organized by time-sampling error, content-sampling error, and interrater differences.  This type of organization gave me a greater understanding of reliability and the methods used in order to estimate reliability.  The Validity chapter also organized the information in a more modern way than I had previously been taught.  I have always learned and understood validity to be broken up into content, criterion, and construct validity.  Although the chapter did include sections on all three, it described all three as falling under construct validity.  Construct validity is used as an umbrella term which is broken down into five sources (Drummond and Jones, 2010).  It became clearer that the purpose is to establish a relationship between assessment scores and the other variables. We are trying to determine if the claims and decisions that are made on the basis of a particular assessment are meaningful and useful for what they are supposed to be accomplishing (Drummond and Jones, 2010).  Another aspect that I appreciated from our text was the brief discussion on the fairness of certain assessments.  “Validity also refers to the adequacy and appropriateness of the uses of assessment results” (Drummond and Jones, p. 100, 2010).  My recent work with multicultural students and counseling has started to interest me in how fair certain parts of the educational system are for their success.  The book points out that a lack of fairness is a lack of validity and this would also show a lack of reliability.  This tells us that we should not be using this assessment to make educated decisions about any student and in particular students from unique backgrounds.

Drummond, R. J. and Jones, K. (2010). Assessment Procedures for Counselors and Helping Professionals. Upper Saddle River, New Jersey: Pearson Education, Inc.