Robert Connors and Andrea Lunsford's "Frequency of Formal Errors"

Robert Connors and Andrea Lunsford discuss the analysis of 3000 teacher-marked essays from the 1980s to discover the most common patterns of student errors and to determine which errors are most often marked by teachers.

The twenty top errors (next to spelling which represents three times the number of grammar errors marked by teachers) include the following:

1. No comma after introductory element
2. Vague pronoun reference
3. No comma in compound structure
4. Wrong word
5. No comma in non-restrictive element
6. Wrong/missing inflected endings
7. Wrong or missing preposition
8. Comma splice
9. Possessive apostrophe error
10. Tense shift
11. Unnecessary shift in person
12. Sentence fragment
13. Wrong tense or verb form
14. Subject-verb agreement
15. Lack of comma in series
16. Pronoun agreement error
17. Unnecessary comma with restrictive element
18. Run-on or fused sentence
19. Dangling or misplaced modifier
20. Its/It’s error

This article is very accessible as they explain their research process and results. They also discuss previous studies and those major findings. Connors and Lunsford also suggest that teachers mark a relatively limited amount of errors and that college students at the end of the century do not make more errors than they did earlier in the century.

I remember reading this when the article first appeared. Connors and Lunsford did the original research to help prepare them to write their college handbook--they wanted to know where to focus their instruction.

Connors, Robert and Andrea Lunsford. "Frequency of Formal Errors in Current College Writing, or Ma and Pa Kettle Do Research." College Composition and Communication 39.4 (1988): 394-409.