Showing posts with label data. Show all posts
Showing posts with label data. Show all posts

Wednesday, August 10, 2011

Grading Clicker Data

The clicker data provided by GMW11 can be assigned grades in many ways. A traditional multiple-choice curve used by GMW11 produced 3 A, 1 B, 24 C, 24 D, and 69 F grades with an average score of 34%.

A typical Knowledge and Judgment Scoring (KJS) distribution, with letter grades set every ten percentage points, would be 1 B, 3 C, 13 D, and 104 F grades. A KJS curve comparable to a right mark scoring (RMS) curve yields 4 A, 3 B, 15 C, 31 D, and 68 F grades with an average score of 49%. The same number, 69 and 68, are passing on each test.

Comparable curving produced similar grade distributions. However, what is being assessed and rewarded is very different. A RMS curve is based on a student’s luck on test day (both in marking and in the selection of questions presented on the test). A KJS curve is based on each student’s self-assessment, it combines knowledge and judgment in selecting questions to use to report what is actually known. Top students earn the same grades by both methods, as do most poor students.

High quality, self-assessing, students earn a reward for reporting what they can trust as the basis for further learning and instruction. The sharper the incline connecting RMS and KJS scores on the chart the higher the quality. High quality students are teachable. KJS identifies them. RMS does not.

By scoring the clicker data by both methods and curving the scores in the same manner, the difference in student performance on the two scoring methods is clearly exposed. The task of the RMS student is to mark the best guess of a right answer for each question. Understanding, problem solving, and reading ability are secondary and even, at times, unnecessary. These are all crucial for a KJS student to determine if a question can be used to report something that is understood or which has sufficient relationships with other information or skills that a verifiable right answer can be marked.

In this day, all multiple-choice tests should offer both methods of scoring. Students can easily switch from lower to higher levels of thinking; from little responsibility to near full responsibility for learning. Successful implementation requires letting students make the switch. Forcing students into KJS is about as unproductive a thing to do as forcing them to mark an answer to every question on a test they cannot understand or at times even read. Power Up Plus scores both methods, as does Winsteps (full credit and partial credit Rasch IRT models). No additional preparation time or effort is needed beyond that required for creating any multiple-choice test.

To the student: Your highest score/grade is obtained by being honest in reporting what you know, understand, and can trust at any level of preparation.

To the teacher: You know what each student can do and understand as the basis for further learning and instruction.

To the administrator: You know the levels of thinking, for each student, and in classroom instruction, as passive pupils prepare to be independent learners (self-assessing, self-correcting scholars).

Knowledge and Judgment Scoring promotes student development when used on essay tests, multiple-choice tests, and I would suggest the same for clicker data.

Wednesday, August 3, 2011

Scoring Clicker Data

I was recently presented with some clicker data to examine (GMW11). It had been scored by traditional right count scoring. There were a number of scores below 20%. There were even four students with a score of zero. That is way below the average guessing score when using five options on each question.

A different score distribution was produced by scoring the data for both knowledge and judgment. This distribution looks very much like what one would expect from students on their first introduction to Knowledge and Judgment Scoring. Students earn the same scores by both methods of scoring when they fail to exercise their own judgment (mark an answer to every question).The top three students therefore obtained the same score with both methods of scoring.

Here is an opportunity to compare Right Mark Scoring (RMS) and Knowledge and Judgment Scoring (KJS) when used on any multiple-choice test. There is one catch, both methods of scoring are being used on one, the same, set of answer sheets.

Normally students would elect which method they felt comfortable using (and if time permits, on the first or second test, they may fill out two answer sheets, one for each method of scoring). The same test data can support a number of different stories. This story will assume that the test was presented with a choice of RMS and KJS, and further, that this was the first such test for the class. Most would be expected to select what they are most familiar with: RMS.


When quantity and quality are scatterplotted from RMS data, the result is a straight line. Only one dimension is being measured: a count of right marks.
 
KJS data are two-dimensional. A range of quality scores can yield the same test score. The test score of 46% was earned by students with a range of quality scores from zero to 44%.

Higher quality students are found above 50%. Lower quality students are found below 50%. Higher quality students get higher scores by marking more right answers. Only one student marked a perfect 100% quality score (no wrong marks).

Lower quality students get lower scores by marking more wrong answers. Four marked a zero quality score (every one of their two to 10 marks on the 23 question test was wrong).

Quantity and quality have been given equal value. The active test score then starts at 50%: 1 point for right, 1 point for good judgment (omit or right), and zero for wrong (poor judgment). [Back in the 1970s, when this work first began, the active test score started with zero. It was called net yield scoring; right minus wrong. The discovery of the quality score produced the second dimension that assesses student performance rather than defaulting to luck on test day.]

The end result of training students to accurately report what they trust they know or can do is shown in the Fall88 scatterplot. After an initial test (such as the clicker data) where most students elect RMS, they change study habits, and voluntarily switch to KJS. Here most of the class show a quality score about one letter grade higher than their test score. There is a bit of a disconnect at the pass/fail line of 60% (70% C, 80% B, and 90% A). Experienced students feel more comfortable reporting what they know than guessing at answers on all items on the test. They are on the path to being independent learners (self-correcting scholars).

This is in contrast to traditional right mark scoring where any score can be one letter grade higher with good luck to one letter grade lower with bad luck than a student’s actual ability. A grade of B one day may be a D on another day. And no one, including the student, knows what the student actually knows and can do as the basis for further learning and instruction.

Grading has an important effect on which scoring method students select: RMS (“I mark, you score”) or KJS (self-assessment, “I tell you”). RMS students tend to cram and to match. KJS students bring a rich web of relationships (from learning by questioning, answering, and verifying) that they can apply to questions they have not seen before. There is an operational difference between remembering and understanding that can be measured (RMS vs. KJS).