After a mixed practice set, the question order is the least useful way to read your results. A better method is to name the skill that failed in each wrong answer and count them. This lesson belongs to mixed original practice.
How do I build an error log?
Make a table with four columns: question, what went wrong, skill category, fix. Keep the “what went wrong” note short and honest.
Useful categories for Combined Science 0653:
- Recall: you did not know the fact.
- Units: the value was right, the unit missing or wrong.
- Graph or table reading: a value or trend was misread.
- Command word: you answered a different question from the one asked.
- Applying a model: you knew the idea but chose the wrong one.
- Arithmetic: a slip in the calculation.
Worked example
All numbers are invented for practice. A student loses marks on ten questions in a mixed set.
| Q | Subject | What went wrong | Skill |
|---|---|---|---|
| 2 | Physics | Wrote 7.5 with no unit | Units |
| 4 | Biology | Read 36 °C as 38 °C on the graph | Graph reading |
| 5 | Chemistry | Described the reaction instead of explaining | Command word |
| 7 | Physics | Forgot the unit again | Units |
| 8 | Chemistry | Misread the scale on the axis | Graph reading |
| 9 | Biology | Did not recall enzyme name | Recall |
| 11 | Physics | Read the wrong row in the table | Graph reading |
| 12 | Biology | Used diffusion for an osmosis question | Applying a model |
| 14 | Chemistry | Read a peak value wrongly | Graph reading |
| 15 | Physics | Left out the unit | Units |
Count by skill: graph reading 4, units 3, command word 1, recall 1, applying a model 1. Total 4 + 3 + 1 + 1 + 1 = 10, which matches the ten questions.
Percentage: graph reading is 4 ÷ 10 = 40% of the lost questions, and units is 3 ÷ 10 = 30%.
By paper order, this looks like errors in all three sciences. By skill, 70% of the loss comes from two habits, and neither needs new content. The next session should be short drills on reading scales and checking units.
The mistake to watch for
A common slip is to write “careless mistake” as the reason.
Mistaken log entry: “Q7: careless.”
This cannot be fixed, because it does not say what to do differently.
A usable entry says what happened: “Forgot the unit after substituting.” The fix then follows: “Write the unit on every line of working.”
Check yourself
1. A student has twelve lost questions: 5 graph reading, 3 units and 4 recall. What percentage is graph reading, to the nearest whole number?
Show answer
5 ÷ 12 = 0.4167, so 42% to the nearest whole number. Check: 5 + 3 + 4 = 12.
2. Another student has eight lost questions: 2 units, 4 command word, 2 recall. Which skill should the next session focus on, and what share is it?
Show answer
Command words, with 4 ÷ 8 = 50% of the lost questions.
3. Rewrite “Q3: silly” as a useful log entry for a graph question where the axis scale was misread.
Show answer
“Q3: misread the scale, each square was 2 not 1. Fix: write the value of one square before reading any point.”
Where this leads next
The log feeds directly into building a balanced repeat session. The mixed practice set gives you material to log, and the scientific investigation critic can help when your errors cluster around experiment questions.
If you cannot see the pattern in your own errors, a teacher in online one-to-one Combined Science tuition can read your marked papers with you and name it.