The purpose of this study was to investigate one individual difference, i.e., rate of response, and the effect on student performance when teachers recognize this difference. Using disadvantaged third grade students as subjects, three null hypotheses were formulated as follows: 1. Slow responding accurate students' (Group LH) scores will show no significant difference over rapidly responding inaccurate students' (Group HL) scores on the Metropolitan Achievement Test when test time-limits are extended. 2. There will be no significant difference on Metropolitan Achievement Test mean scores between students allowed longer daily work-limits during the school year and those students using regular daily work-limits during the school year. 3. There will be no significant difference on Metropolitan Achievement Test mean scores between students allowed longer daily work-limits during the school year and those students using regular daily work-limits during the school year when test time-limits are extended. The t-test was applied for hypothesis number one and the analysis of variance F-statistic was used for both hypotheses two and three. Findings: The findings of this study indicated the acceptance of null hypothesis number two and the rejection of null hypotheses numbers one and three. Rejection of hypothesis number one lends support to the belief that some children exist that are slow responding but not mentally low. Hypothesis number three lends support to the belief that time to work accurately is an important factor for some children and that test time-limits may impose a penalty on these children rather than measuring accurately the child's abilities or skills. Further Findings: These disadvantaged third graders with an overall mean I.Q. of 97 managed to respond to practically every question on six subtests and about half of the students finished the seventh subtest easily within the standard time limit. On one mathematics subtest, Mathematics Computation, only four students out of 230 did not complete the answer sheet within the standard test time-limit. Participating teachers remarked that some children were 'finished" with the answer sheet before all of the test booklets had been distributed and that most of the children work for awhile, become totally frustrated, and then arbitrarily fill in the remaining answers. Recommendations: In view of the findings of this study, the writer offers the following recommendations. 1. To testing departments of public schools and to test publishers: Standardized tests need to be redesigned to provide a strong incentive to the test taker to "try" each question, whether the incentive be a reward, recognition, or just fun to do. At the present time and using present standardized tests, these disadvantaged children really have no reason to do anything but use the answer sheet for drawing geometric designs. 2. To school boards and state legislators: Strong objections should be raised in the use of present standardized achievement tests in fulfilling accountability law requirements. 3. To schools of education and students involved in research: With some gain apparent with informed groups (students given longer work-limits and aware teachers) in this study and with the successful research cited in Chapter II, further study into teacher expectancies with disadvantaged children is vital. 4. To school administrators and teachers: Revise testing procedures to improve teaching-testing feedback for children, This could be accomplished through in-service education of administrators and teachers.