The standard score is an estimation of your logical ability, compared to Alva’s norm group.
The most common standard scores are 5 and 6. The percentile range for these scores is wide due to the fact that it covers 38% of the norm group. Standard scores above 9 or below 2 are much less common.
Keep in mind when interpreting your results that logic ability is far from the only thing determining job performance or career success. Factors such as personality, motivation, values, and experience are also important, and strengths in one area may outweigh weaknesses in another.