Are Pre Test Placement scores ACCURATE?

Prior to training, many trainers ensure they profile their participants.

There are variety of diagnostic assessments and placement tests to determine the level of course needed. 

Recently TLMM team had a changeling time with certain level of English (Writting and Communicating) scores which client could not understand and come to acceptance on the results the trainer have given them. 

Here are the questions posted by client:

1. Why are the scores given by the trainer not the same as how we predicted to be?
2. The participant that we assume to be bad at the test had amazing results?
3. The participant has been working in our company for the last 10 years and we have clearly identified him to be bad at Written and spoken English.  But because the participant showed a confidence during the spoken English, the score for this participant is above than average.  Is that possible?
4. My participants may have limited knowledge at the beginning of the program that prevents them from accurately assessing baseline answers, compared to another participant who may have already prepared. How is this possible?


Well, TLMM could not come up with any research as of yet to proof the reliability of placement scores before training.