The purpose of this study was to investigate the reliability and validity of a newly developed survey instrument, the "Primary Practices Questionnaire" ("PPQ"), designed to measure first, second, and third grade teachers' perceived use of developmentally appropriate practices. The initial item pool was reviewed for content validity by a panel of four content experts. Several teacher focus groups also contributed to the revision of item wording. The final survey consisted of 41 items. Sampling yielded 215 responses. Reliability was measured through an internal consistency method. Cronbach's a = 808 indicating the instrument has good reliability. Construct validity was examined through three separate analyses. A factor analysis was conducted to uncover if factors were revealed from the survey responses. ANOVA, independent samples t-test, and correlation were used to see if variables that previous literature found as influential on DAP had a similar relationship with the "PPQ" results. Lastly, correlation was used to investigate the relationship between the responses on the "PPQ" to another instrument, the "Beliefs about Primary Education Scale." The "Primary Practices Questionnaire" appears to have an underlying two factor structure, however this finding is considered tentative. First grade teachers over third grade teachers and teachers who engage in higher numbers of different types of professional development activities (recency and content not examined) reported higher levels of implementation of developmentally appropriate practices. These two findings are consistent with previous research. Other teacher and context variables measured, such as certification, level of education, total years teaching, autonomy in curricular and instructional decision making, class size, and classroom support did not results in between groups differences on the "PPQ" which is inconsistent with previous research. The "PPQ" shows some evidence of construct validity as it has a moderate positive correlation (r = 0.34) with a theoretically related instrument. In all, the results of the investigation into the psychometric properties of the Primary Practices Questionnaire provide a promising start for further development of the instrument. It is hoped the creation of this instrument will go far in creating an understanding in the greater public education community of the need to promote the use of developmentally appropriate practices. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]