Carmen Campbell (P) applied for disability benefits and her application was denied. She requested a hearing de novo before an Administrative Law Judge. He determined that her back problem was not severe enough to find her disabled without further inquiry, and accordingly considered whether she retained the ability to perform either her past work or some less strenuous job. P retained the physical capacity to do light work. P was 52 years old, that her previous employment consisted of unskilled jobs, and that she had a limited education and experienced difficulty in speaking and writing English. She was able, however, to understand and read English fairly well. The Administrative Law Judge found that a significant number of jobs existed that a person of P's qualifications could perform. This determination was upheld by both the Social Security Appeals Council, and the District Court for the Eastern District of New York. The Court of Appeals for the Second Circuit reversed finding that the medical-vocational guidelines did not provide the specific evidence that it previously had required. It concluded that the Secretary had failed to introduce evidence that specific alternative jobs existed, the determination that P was not disabled was not supported by substantial evidence. The Supreme Court granted certiorari.