Science Proficiency and Course Taking in High School


 
  



  

 

Science Proficiency and Course Taking in High School
The Relationship of Science Course-taking Patterns to Increases in Science Proficiency Between 8th and 12th Grades


                

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Science Proficiency and Course Taking in High School
The Relationship of Science Course-taking Patterns to Increases in Science Proficiency Between 8th and 12th Grades

Timothy Madigan Bureau of the Census


                

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Foreword
Relatively little attention has been given to the relationship between course taking and achievement in science. This report examines factors related to gains in science proficiency between 8th and 12th grade. This analysis uses achievement testing and transcript data in the National Education Longitudinal Study of 1988 (NELS:88) to investigate how changes in science proficiency are related to science course-taking histories of high school students. Like an earlier report by Rock, Owings, and Lee (National Center for Education Statistics 1994) on changes in the mathematics proficiency of students between 8th and 10th grades, the analysis takes into account initial proficiency of students—a crucial characteristic related to both gains in proficiency and course-taking patterns. This focus enables the reader to understand how course-taking patterns are related to gains in proficiency among students who in eighth grade were at the bottom, middle, and top of the science proficiency distribution. The report also explores the extent to which gains in science proficiency are related to student race-ethnicity, gender, and socioeconomic background, after accounting for differences among these groups in science course taking. Mary Frase Acting Associate Commissioner





Table of Contents
Foreword....................................................................................................................................................... iii Acknowledgments ...................................................................................................................................... vii Highlights ................................................................................................................................................... viii Introduction .................................................................................................................................................... 1 Science Proficiency Levels .............................................................................................................................2 The Science Proficiency Level of Students and Changes Over Time.........................................................2 Science Course-taking Patterns and Gains in Science Proficiency Level...................................................4 Science Course Taking and Gains in Proficiency Level by 8th Grade Proficiency Level ................................................................................................................................................................6 Increases in Proficiency Level, Type and Number of Science Courses, and Demographic Factors: A Multiple Logistic Regression Approach ...........................................................7 Exploring How Gender, Race-ethnic, and Socioeconomic Differences in Chances of Increasing in Science Proficiency Level Are Influenced by Variation in Science Course Taking...................................................................................................................................9 Summary....................................................................................................................................................... 11 Appendix A ..................................................................................................................................................16
Logistic Regression..........................................................................................................................24 Appendix B: Technical Notes for NELS:88 ...............................................................................................25
Respondents Who Were Missing Key Information......................................................................26 Sampling Errors ...............................................................................................................................28 Variables Used in Analysis .............................................................................................................29 References .....................................................................................................................................................31



List of Tables
Table 1. Percent of 1988 8th-grade students whose science proficiency level decreased, remained the same, or increased between 1988 and 1992, by selected school and student characteristics .................................................................................................................................................4
Table 2. Percent of 1988 8th-grade students who took various semesters of science and types of science courses in high school by selected school and student characteristics ....................................5
Table 3. Percent of 1988 8th-grade students whose science proficiency increased by one or more levels between 1988 and 1992 by 8th-grade science proficiency level, semesters of science, curriculum, and science courses taken in high school..................................................................6
Table 4. Estimated logistic regression coefficients for the regression of increase in science proficiency level between 1988 and 1992 on student, school, and course-taking characteristics by science proficiency level in 8th grade......................................................................................................8
Table 5. Logistic regression coefficients for contrasts of interest in models predicting changes of increasing in science proficiency level with and without controls for course taking ........................10
Appendix A
Table A1. Standard errors for table 1.........................................................................................................16
Table A2. Standard errors for table 2.........................................................................................................17
Table A3. Standard errors for table 3.........................................................................................................18
Table A4. Data for Figure 1: Percent of NELS students at different levels of science proficiency: 1988 and 1992 ...............................................................................................................................................19
Table A5. Standard errors for table A4......................................................................................................19
Table A6. Percent of NELS students at various levels of science proficiency in 1992...........................20
Table A7. Percent of 1988 8th-grade students whose science proficiency level decreased, remained the same or increased between 1988 and 1992 .........................................................................21
Table A8. Estimated logistic regression coefficients for the regression of increase in science proficiency level between 1988 and 1992 on student, school, and course-taking characteristics..........22
Table A9. Estimated odds ratios for the logistic regression coefficients in table 4 ................................23
Appendix B
Table B1. Percentage of respondents who were missing key information, by demographic and schooling characteristics.......................................................................................................................27


List of Figures
Figure 1. Science proficiency levels of NELS students at two points in time ..........................................3 Figure 2. Change in science proficiency levels of 1988 8th-graders between 1988 and 1992, by proficiency level in 1988 ................................................................................................................................3 Figure 3. Percent of 1988 8th-grade students who increased in science proficiency level between 1988 and 1992 by semesters of science taken in high school.......................................................6 Figure 4. Percent of 1988 8th-grade students who increased in science proficiency level between 1988 and 1992 by type of science courses taken...........................................................................6



Acknowledgments
The author would like to thank all those who helped in the production of this report. Nabeel Alsalam, Mary Frase, and Jeffery Owings from the National Center for Education Statistics (NCES) provided abundant feedback from start to finish. Paul Siegel and Suzanne Bianchi from the Census Bureau provided many useful suggestions. Mary Pontorno and Christopher Gaebler from the Census Bureau and Bruce Daniel from Pinkerton Computer Consultants, Inc. provided data and programming assistance. A host of additional reviewers helped by providing invaluable comments or advice. They include Larry Suter from the National Science Foundation; Sentra Raizen of the Center for Science Improvement; Thomas Hoffer of the National Opinion Research Center; Don Rock and Judy Pollack of Educational Testing Service; Robert Burton, Sue Ahmed, Andrew Kolstad, and Jeanne Griffith from NCES; and Deborah Carter from the American Council for Education. Rebecca Pratt and Carol Rohr from Pinkerton Computer Consultants, Inc. and Margaret Harding from the Census Bureau provided help with desktop publishing and graphics production.




Highlights

A number of previous cross-sectional studies have found a strong relationship between a student’s course-taking history in science during high school and his or her current achievement in science. However, it has been difficult to interpret this evidence as the effect of course taking. It is equally plausible that students who take more science courses or more difficult science courses would also have been high achievers if tested before high school. With extensive longitudinal data on both achievement and course taking now at hand, a more definitive analysis is possible. This analysis uses data on science achievement and transcript reports of science course taking of students from the National Education Longitudinal Study of 1988 (NELS:88) to estimate the relationship between their science course taking and the change in their science proficiency level between 8th and 12th grades.

How many students increase in science
proficiency level between 8th and 12th grades?
Fifty-four percent of students showed an increase in their science proficiency level, while 35 percent stayed at the same level and 11 percent declined. The chances of increasing in science proficiency level varied with the demographic and academic characteristics of students.

Is taking more science courses related to gains in
science proficiency level between 8th and 12th grades?
Generally speaking, taking eight or more semesters of science was positively associated with increasing in science proficiency level. This result held in most situations even after accounting for the association between socioeconomic status (SES), achievement level in eighth grade, gender, and race-ethnicity on the one hand and both course taking and increasing in science proficiency on the other. The number of science courses taken was not, however, the only information about course taking available in NELS:88. Information on the level of science course taken was also available and proved useful.


Is taking advanced level science courses such as
physics and chemistry related to gains in science proficiency between 8th and 12th grades?
For students who started at the top science proficiency level in eighth grade, taking more advanced science courses was related to increases in science proficiency level. Furthermore, after controlling for level of science course taken, evidence of a positive relationship between the number of science courses and chances of increasing in science proficiency level was not found. Taking challenging science courses seems to be crucial for high initial achievers.
For students who started at low to middle levels of science proficiency in eighth grade, both taking advanced level science courses and a higher number of science courses were related to increasing in science proficiency level.

Are demographic characteristics of students related
to chances of increasing in science proficiency level during high school?
The answer is yes. Asian and white students were more likely than black and Hispanic students to increase in science proficiency level. Students of parents with high levels of education, occupational rankings, and incomes (i.e., high SES) were more likely to increase in science proficiency level than students of parents with lower levels.

After accounting for differences between
demographic groups in the number and level of science courses taken, do differences in their chances of increasing in science proficiency level disappear?
Gender, race, and familial SES continued to exhibit a relationship to chances of increasing in science proficiency level even after adjusting for differences in science course taking. In future research on this topic, researchers might consider alternative intervening variables or ways of extracting more information out of the coursetaking variables.






Introduction
Some people are concerned that our nation’s students are being out-paced in scientific literacy by students from other advanced, industrial nations.1 Many education professionals and policymakers have outlined solutions to this problem. Increasing the number of science courses required for high school graduation, some have argued, will help students in the U.S. progress toward becoming first in the world in science achievement.2 Others have called for an integrated approach to science which continuously exposes all students to science material throughout high school.3
These recommendations for more exposure to science are based in part on research that has documented a positive relationship between course taking and achievement.4 Jones et al.5 found a positive relationship between total number of science (and mathematics) credits a high school student took and his or her science proficiency level in 12th grade. Mullis and Jenkins 6 also found a positive relationship between course taking and proficiency, but questioned the nature of the relationship because brighter students may simply take more courses.
In the area of mathematics, Rock, Owings and Lee7 have shown course taking to be positively related to increases in a student's proficiency level between 8th and 10th grades. Among students who started at the same proficiency level in eighth grade, those who took higher level mathematics courses were more likely to increase to higher proficiency levels two years later than students who did not take higher level courses. Their results suggest that course taking affects mathematics proficiency. More importantly, they show that taking more advanced mathematics courses seems to help both low and high achievers.
Differential course-taking patterns may be responsible for part of the gap between the mathematics and science achievement of high school males versus females and of whites and Asians compared to blacks and Hispanics.8 Blacks and Hispanics take fewer mathematics and science courses than whites and Asians and the science courses they take are clustered at lower levels.9 High school males are less likely to stop

taking science and mathematics courses than females.10 Indeed, in mathematics, Rock, Owings and Lee found that the types of mathematics courses males and females took explained some of the difference in gains in mathematics proficiency levels between 8th and 10th grades. Furthermore, research comparing public and private schools and on effective schools in general has found that good schools are often organized around a challenging academic or college preparatory curriculum.11
This report uses longitudinal data to examine whether students at the same level of science proficiency during eighth grade have higher science proficiency levels four years later if they took more semesters of science in the interim as compared to students who took fewer semesters of science. It will ascertain the relationship between taking challenging science courses in high school and experiencing gains in science proficiency. In addition, the relationships among school and student characteristics, high school curriculum and changes in proficiency level are also examined.
The analysis begins by describing the distribution of students across levels of science proficiency, the amount of change in proficiency between 8th and 12th grades, and the course-taking patterns of students. The relationship between increases in proficiency level and science course taking while controlling initial proficiency level is then examined. Results from this section should be useful to people who ponder whether lowachieving students would benefit from tougher course-taking standards. Finally, the relative influences of family background, student demographic characteristics, and school and course-taking factors on chances of increasing in science proficiency level are modeled with multiple, logistic regression.
Data from the National Education Longitudinal Study of 1988 (NELS:88) were analyzed in this report. These data provide the best available resource to examine growth in science proficiency during high school. Other non-longitudinal national surveys have provided only crosssectional snapshots of the relationship between course taking and achievement. This does not facilitate the testing of causal relationships. Previous longitudinal surveys sponsored by the