Answer: TIMSS scale scores range from 0 to 1 000 (although learner performance typically ranges between 300 and 700). The TIMSS achievement scales were established in TIMSS 1995 based on the achievement distribution across all participating countries, treating each country equally. The scale centerpoint of 500 was set to correspond to the mean of the overall achievement distribution, and 100 points on the scale was set to correspond to the standard deviation. Achievement data from subsequent TIMSS assessment cycles were linked to these scales so that increases or decreases in average achievement may be monitored across assessments.