Reading Item with a Defensible Distractor
A 45-candidate trial of a 20-mark reading paper includes an inference item on a passage about a grandmother's vegetable garden. The key is C: 'She is careful with money.' The item statistics show difficulty 0.31 and discrimination 0.18; 14 of the 16 candidates in the top quartile chose D: 'She is anxious about being cheated.' The relevant sentence reads: 'She counted the coins twice, not because she doubted the buyer, but because the school fees were due on Friday.' The passage also says she has sold at the same market for 19 years. One moderator argues the item is valid because D contradicts the 'not because' clause; another argues it should be dropped because high-achievers read the sentence as irony. The paper has already been printed for the main session in three weeks. The syllabus requires inference, not literal retrieval.
1. Diagnose the item. Is the problem in the key, the distractors, the passage, or the candidates' reading? Use the statistics and the sentence.
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The key is defensible: the sentence explicitly says 'not because she doubted the buyer'. D therefore contradicts the passage unless the candidate reads irony, and nothing else in the passage supports irony. The problem is not a wrong key; it is a trap that rewards close attention to negation rather than inference. Difficulty 0.31 is low but acceptable for an inference item; discrimination 0.18 is the real warning. With only 45 candidates, 14 of 16 top-quartile choices for D is a strong signal that the item is measuring sensitivity to a syntactic construction, not the intended skill. That does not make C wrong, but it makes the item a poor discriminator. Diagnose: key sound, distractor too attractive, passage not ambiguous enough to justify accepting D.
2. Recommend one action for the printed main session: retain, accept both C and D, drop, or revise. Justify with fairness and validity.
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Retain C and do not accept D. Accepting both would reward a misreading of an explicit clause and would be unfair to candidates who read the sentence correctly. Dropping the item after printing would change the total mark and require rescoring all 45 scripts, with little gain because the key is not wrong. The better action is to keep the item, brief markers not to accept D, and flag it for post-session review. If the item is later used again, replace D with a distractor that does not depend on the negation. The low discrimination is a review issue, not a scoring-error issue; it should not be solved by changing the key after the event.
3. Rewrite the item to test the same inference without the negation trap. Provide a new stem and four options, and explain why it is better.
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New item: 'The writer mentions that the grandmother has sold at the same market for 19 years mainly to show that - A she is experienced and trusted; B she is afraid of change; C she is poor; D she dislikes the buyer.' Key A. This tests inference from a detail without the 'not because' trap. It still requires candidates to connect a detail to character, but the distractors are not built on a syntactic negation. If the original sentence must be kept, ask: 'Why does the writer say she counted the coins twice?' Key: because school fees were due, not because she distrusted the buyer. That is more literal. The revised item should be trialled on at least 30 scripts before reuse.