- Lack detail
- Strongly underertimates small firms , design , production enginerring , and software
- Uneven propensity to patent
- Misses software
- Measure of significance
- Cost of collection
- Misses incremental changes
- Variable definition of innovation
- Cost
- Misses in house process innovations and incremental product improvement
- Possible manipulation by marketing and public relations
- Lack of homogeneity of equalifications
- Finding independent experts
- Judgements beyond expertise