Wednesday, December 21, 2011

True Score Diviner

The previous few posts have listed weaknesses in traditional multiple-choice right mark scoring (RMS). Other than a rank of increasingly questionable value as the test scores decrease, RMS results are seriously flawed for use in current formative assessments. Quality and quantity are still linked. They are not linked in projects, reports, and essay tests. Even on a failing project, there can still be a note, “Great use of color”; “Great idea, another bit of editing and a great paper”.

Knowledge and Judgment Scoring (KJS) does the same thing with multiple-choice tests, “You got a quality score of 90% on the test you select to mark. Now make the same preparation on more of the assignment and you will have a passing score. We know you can do it!”

RMS test scores are always suspect and often meaningless. The True Score Diviner can help you find your true score, or if your score is your true score, the range of test scores you may have gotten with the same preparation. 

At 100%, your test score and true score are one and the same. With a test score of 25%, on a 4-option question test, your true score could range from 25 - 25 or zero to 25 + 25 or 50%. Half of the time RMS cheats you and half of the time it teases or lies to you. You have a lucky day or an unlucky day. There is no way to know which or how much from a single test. Statistical procedures say very little about single events strongly related to luck. They can help if you took about five versions of the test and calculated an average test score. You do not do that.

Knowledge and Judgment Scoring (KJS) solves this problem by letting you report what you know and trust. You are, in effect, scoring your own test based on your own preparation. Each student gets a customized test. Guessing is not required.

Now both student and teacher know what every high quality student knows and can do that can be trusted as the basis for further instruction, learning, and application regardless of the test score. Quantity and quality each generate separate scores.

We need to promote Knowledge and Judgment Scoring (KJS). Power Up Plus (PUP) does this by offering students both RMS and KJS. They make the switch when they have matured enough in a supportive classroom that places equal emphasis on knowing and on the skills required by the successful independent achiever. I know. I don’t know. I know how to know.

RMS today makes as much sense as selling gasoline at $3 per gallon from a pump that averages one gallon for each $3. It may deliver less than ½ gallon to over two gallons for each $3. But it does deliver an average of $3 per gallon if you sum all the customers for the day. That is a range of less than $1.50 to over $6.00 per gallon. Such a situation in academic measurement still goes, for the most part, unquestioned.

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