**Core Concept**
Kocher's criteria are a set of clinical signs used to diagnose septic arthritis of the hip in children. The criteria aim to differentiate between septic arthritis and transient synovitis, a common cause of hip pain in children.

**Why the Correct Answer is Right**
Kocher's criteria include six clinical signs: limited range of motion in all planes (especially internal rotation), limp, refusal to bear weight, fever, abdominal pain, and a positive "barlow" sign. These signs are used to estimate the likelihood of septic arthritis.

**Why Each Wrong Option is Incorrect**
**Option A:** Limited range of motion in all planes is actually a component of Kocher's criteria, making it an incorrect choice.
**Option B:** Refusal to bear weight is a component of Kocher's criteria, so it's not the correct answer.
**Option C:** Fever is a component of Kocher's criteria, which makes this option incorrect.
**Option D:** A positive "barlow" sign is a component of Kocher's criteria, so this option is also incorrect.

**Clinical Pearl / High-Yield Fact**
Kocher's criteria are not specific for septic arthritis and should be used in conjunction with other diagnostic tools, such as imaging studies and laboratory tests, to confirm the diagnosis.

**Correct Answer: D. A positive "barlow" sign is not a component of Kocher's criteria for diagnosing septic arthritis of the hip.**