Chapter 3: How Scoring Works, and Why the Side Matters Most

The big idea: Your rating is compared to a consensus answer key. Matching it earns full credit, missing by one rung on the same side earns half, and crossing to the wrong side earns nothing. So getting the side right is most of your score.
Carry it into the exam as: First decide effective or ineffective. Only then decide how strongly. The side is where the points are.

Where the answer key comes from

Your ratings are not graded against one professor’s opinion, and not against some clever hidden answer. The key is built from the consensus of medical school representatives: groups of people from admissions, faculty, and student affairs who rate the same responses, and whose collective judgment becomes the standard. When a response is keyed “Very Effective,” it means the people who train and supervise medical students broadly agree that it is a strong move.

This is good news, because it tells you what to aim for. You are not trying to guess a trick. You are trying to think the way an experienced, fair-minded medical educator thinks. That mindset is learnable, and most of this book is about installing it.

The partial-credit engine

PREview does not score each item as simply right or wrong. It gives partial credit based on how close your rating is to the key, with one crucial twist about which side of the scale you land on.

Here is the rule:

Your rating compared to the key	Credit
Exact match	Full credit
One rung away, on the same side	Half credit
On the opposite side	Zero credit

The official illustration makes it concrete. Suppose the key for a response is Effective.

You rate it Effective. Exact match, full credit.
You rate it Very Effective. One rung away, but still on the effective side, so half credit.
You rate it Ineffective. Also one rung away on the scale, but it crosses to the ineffective side, so zero credit.
You rate it Very Ineffective. Opposite side, zero credit.

Read those last two lines again, because they contain the most important strategic fact about this exam.

The side rule

Look at what happened with the key of “Effective.” Rating it “Very Effective” and rating it “Ineffective” are both one position away on the four-point scale. They feel equally close. But one earns half credit and the other earns nothing, because one stayed on the correct side and the other crossed over.

We will call this the side rule: the boundary between the effective side and the ineffective side is the expensive one. Getting the side right but the strength wrong costs you half of one item. Getting the side wrong costs you the whole item, even when you were only one rung off.

The practical consequences are large, and they should reshape how you rate:

Decide the side first, and decide it carefully. Before you fuss over Effective versus Very Effective, lock in whether the response helps or hurts. That single decision is worth more than the fine-tuning.
Do not agonize over the fine-tuning. Once you are confident a response is on the effective side, the gap between Effective and Very Effective is only half credit at stake. If you are torn, pick one and move on. The clock is better spent making sure your next side call is right.
Slow down on responses near the line. The responses that sit close to the boundary, the ones that are only mildly helpful or mildly harmful, are where points are won and lost, because that is where it is easiest to fall onto the wrong side.

A quick look at the math

You never calculate your own score, but seeing how credit stacks up makes the side rule vivid. Imagine two students rating the same six responses.

Response	Key	Student A	Student B
1	Very Effective	Effective	Ineffective
2	Effective	Very Effective	Effective
3	Ineffective	Ineffective	Effective
4	Very Ineffective	Ineffective	Ineffective
5	Effective	Effective	Very Ineffective
6	Very Ineffective	Very Ineffective	Effective

Student A never matched exactly on items 1, 2, and 4, but stayed on the correct side every single time. A earns half credit on 1, 2, and 4, and full credit on 3, 5, and 6. That is a strong performance.

Student B matched exactly on items 2 and 4, which looks fine in isolation, but crossed to the wrong side on items 1, 3, 5, and 6. Those four are worth zero. Two perfect answers and four zeros is a weak performance, far below Student A, who never nailed an inner answer exactly yet never crossed the line.

The lesson in one sentence: consistency about the side beats precision about the rung. A student who reliably tells help from harm will out-score a student who sometimes nails the exact word but sometimes flips to the wrong side.

Independent scoring, the score, and the rest

A few more facts to round out the picture:

Each response is scored on its own. Just as you rate them independently, credit is summed across all scored responses. There is no bonus for getting a whole set “right” and no penalty that ties responses together.
Some responses do not count. As noted in Chapter 2, unscored field-test items are mixed in and not labeled, so rate everything with equal care.
Your total becomes a 1 to 9 score, reported with a percentile rank (how you did relative to other examinees) and a confidence band (a range that reflects normal measurement noise). The single digit is the headline number schools see.
You decide whether to keep the score. At the very end you get a one-time, roughly ten-minute window to keep your score or void it. Voiding means no school sees it, but it still counts as one of your limited attempts. We cover how to make that call in Chapter 13. Short version: do not void on test-day nerves.

Key takeaways

The key is the consensus of medical school representatives, so aim to think like a fair, experienced educator rather than to guess a trick.
Credit is full for a match, half for one rung away on the same side, and zero for the opposite side.
The side rule: crossing the effective/ineffective line is the costly error. Decide the side first and carefully, then fine-tune.
Consistency about the side beats precision about the rung. Never crossing beats sometimes perfect, sometimes flipped.
Your total scales to a 1 to 9 score with a percentile and confidence band, and you get one chance at the end to keep or void it.