General chemistry workshop attendance and improved student

Dec 1, 1993 - Journal of Chemical Education · Advanced Search. Search; Citation; Subject. Search in: .... Keywords (Domain):. Chemical Education Resea...
3 downloads 0 Views 3MB Size
General Chemistry Workshop Attendance and Improved Student Performance James W. Hollister Learning Skills Center, University of California,Davis, CA 95616 Many universities offer supplemental courses or workshops to help students improve their performance in general chemistry. Cornell University, the University of California, Davis (U. C. Davis), U. C. Irvine, and U. C. Riverside all have staff specialists that lead such workshops ( 1 3 ) .Turner (1)found statistically significant differences between the final grades of students who regularly attended such workshops and the final grades of nonattending students. Deal (21, however, reported the higher grades found in his study not to he statistically significant. Clearly, variables other than workshop attendance may account for a student's fmal grade in a course, among them the student's mathematical ability and motivation. As a test of the effectivenessof a sewnd-quarter general chemistrv (Chemistrv 1H,workshoo offered at U. C. Davis. I collecteh data to deie-ne which variables significantly: influenced the students'final Chemistry 1B wurse grades. The variables assessed were the students' Mathematics ScholasticAptitude Test (MSAT)scores, the students' Verbal Scholastic Aptitude Test WSAT) scores, the number of workshop sessions the students attended, the students' perceptions ofthe average number of hours per week spent reading the chemistry text and notes, and the students' perceptions of the average number of hours per week spent solving chemistry problems. The averages of hours spent reading and solving problems served as a measure of motivation. General Chemistry l B Approximately one half of the undergraduate students a t U. C. Davis take General Chemistry lAand 1B. General Chemistry 1B is a five-unit course given both in the winter

and spring quarters. The prerequisite for Chemistry 1B is a ~assinrrmade in Chemistrv 1A. Three different Chemist& 113 snitions with an e n r h n e n t of approximately 430 students each are offeredin the winter Quarter.These sections consist of three one-hour lectures and a one-hour discussion session per week. The discussion sessions are led by teaching assistants. In addition, Chemistry 1B has three hours of laboratory per week. In 1989, Chemistry 1B topics included: liquids and solids, wlligative properties of solutions, chemical equilibria, acid-base chemistry, solubility and precipitation reactions, oxidation-reduction reactions, entropy and Gibbs energy, electrochemistry, and qualitative analysis. The Workshop The workshop, titled General Assistance in Chemistry lB, is offered by the Learning Skills Center and is open to all Chemistry 1B students. It is free, carries no credit, and attendance is optional. There are two sections of the same workshop and each meets twice a week for the entire quarter. The pace of the topics covered in the workshop sessions generally parallels the pace of wurse topics presented in lecture. At the beginning of the quarter the professor announces the workshop duringlecture. The workshop is led by the same staff specialist for the entire quarter. The first Chemistry 1B workshop session reviews basic study skills. Thereafter, the workshops are more coursespecific. In a typical workshop session, the specialist reviews new concepts, answers questions on course homework, and gives test problems used in previous Chemistry 1Bwurses. The specialist discusses solutions aRer the students have had time to attempt the problems themselves. Handouts, given throughout the quarter, summarize im-

Volume 70 Number 12 December 1993

1013

portant wncepts, give algorithms, or offer hints and mnemonic devices. Two days before each examination, the specialist gives a n evening practice test session for one hour. Solutions are discussed in the following hour. The specialist also schedules regular office hours, both by appointment and on a drop-in basis, for most days of each week. I n the winter auarter of 1989. the combined average attendance of both workshop sessions was about 75 stndents. This is about 6% of those who received a final grade for Chemistry 1B. The attendance in evening practice test sessions was as high as 110 students, or about 9% of those who received a final grade in the course. Workshop students represent a broad range of abilities. A high per&mtage of student; earn A or B grades in the course, but students who have earned lower grades have never complained about these students attending. I n their evaluations of the workshops, most students of all ability levels express appreciation for the reviews of concepts and especially for practice problems. Many students feel they have a better understanding aRer practicing on old test problems. As pointed out by Turner ( I ) , the presence of students who earn A and B grades in the workshop removes any perception of the workshop as remedial and helps integrate all workshop students into the chemistry wurse.

-

The Statistical Analysis I used a stepwise multiple regression analysis to determine if stndents'fmal Chemistry 1B course grades, the dependent variable, were influenced significantly by the following independent variahles: (1) The students'MSAT scores. (2) The students' VSAT scores. (3) The number of workshop sessions the students attended. (4) The students' perceptions of the average number of hours per week spent reading the chemistry text and nates. ( 5 ) The students' perceptions of the average number of hours per week spent solving chemistry problems.

Careful telephone interviews using a written protowl yielded the average number of hours per week students spent in reading and solving problems. The analvsis eliminates students for whom anv data was missing. ~ h c l n d e only s students who attendedkither one of two different Chemistry 1B sections taught by the same professor. Also, the analysis includes only students who actually had attended a t least one workshop session, and this before the first midterm. Thus, the study does include data for students who decided the workshop was not for them. It excludes, however, data for students who might have benefited from the workshop but attended no sessions. Results and Discussion A regression model was built using a stepwise multiple regression analysis of the variables for 86 students. The regression equation is:

Final Gmde = 0.473 + 0.004 MSAT - 0.002 VSAT + 0.068 Workshop Hours The predicted Final Grade is a numerical value from 0.00 (representing an F grade) to 4.00 (representing an A grade). The independent variables MSAII: VSAT, a n d Workshop Hours are preceded by their slope values. The intercept is 0.473. The three-digit grade derived from the equation is a point estimate and should not be viewed as iidicating thrke significant figures. The true grade must be within the confidence limits as described below. Residuals analysis indicated no problems with the model. The F-test value for the regression equation is

1014

Journal of Chemical Education

1.s-I 0

2

4

8 10 12 14 16 18 Workshop Hours

6

:

Plot of the regression equation of the final grade versus number of hours of workshop attendance (FinalGrade = 0.473 + O.O04(MSAT) - 0.002(VSAT)+ 0.068 Workshop Houn). The averages of verbal (444)and math (561)SAT scores for the studied group were entered into the equation. The center line represents the regression line and the two outer lines represent the confidence limits (95%).

Table 1. Partial F Test and Significance Level Values for Variables

Variables MSAT VSAT Workshop Hours

Panial F Test 15.87 4.43 19.12

Significance Level 0.01% 3.83% 0.01%

16.68 and is signif~canta t the 0.01% level. Thus, the eqnation pives a reasonable model to oredict the final made in " the course. The variables which fit the equation explain about 38% of entire variability of the final grades, as shown by the coefficient of multiple determination, R2, which is 0.379. Although there is about 62% of variability left unex~lained.the partial F test values (Table 1)take this varinhility into Ansideration and demonstrate thut the variable of workshoo hours is a simificant and useful oredictor of final course grade. Another way of viewing the unexplained variability is to look a t conlidence intervals. The 95% confidence intewals for the plot of the regression line using the averages for MSAT and VSAT scores are shown in the figure at the top right. The true regression line must lie within the wnfidence limits envelope 95% of the time. Stepwise regression shows that motivation as measured by student perceptions of average weekly hours spent reading and solving problems is not a significant predictor of fmal course grade. All of the above results are virtually identical to the results obtained when the total points earned in the course by each workshop student are used as the dependent variable rather than the student's final letter grade (as represented by a numerical value from 0.00 to 4.00). Example of Using the Mcdel: The 0.068 slope value for workshop hours predicts that a class of students who at-

-

~

-

~~~

Table 2. Averages of Variables for Students

Students Foreign

MSAT VSAT Work- Reading Problem- Grade Score Score shop Hours Solving Hours Hours 571

367

8.8

6.1

8.5

3.14

U.S.. Non- 572 Caucasian

463

9.5

5.1

5.5

2.72

493

6.4

5.8

6.7

2.13

444

8.3

5.6

6.7

2.67

(n= 25)

(n= 35)

U.S.. 536 Caucasian (n= 26) All

561

Students (n= 861

Table 3. Percentage of Student Groups with MSAT Scores 100 Points or More above VSAT Scores

Students Foreign (n= 25) U.S., Non-Caucasian ( n = 35) U.S., Caucasian (n= 26)

Percent 84% 57% 31%

tended 10 workshop sessions would increase their grade by 0.68 grade points [(10)(0.068)= 0.681 or about 0.7 of a letter grade value. The 0.004 slope value for the MSAT score predicts that a class of students with an average score 100 points higher than another class of students would receive a letter grade 0.4 grade points higher than that of the lower MSAT score students [(100)(0.004)= 0.41. The -0.002 slope value for the VSAT score predicts that a class of students with an average score 100 points higher than another class of students would receive a letter grade 0.2 grade points lower than that of the lower VSAT score students [(100)(-0.002) = -0.21. The surprising negative correlation of higher VSAT scores with a slightly lower grade may be explained by a relatively high incidence of workshop students for whom Englishmay be a second language. In this analysis, 29% of the students were not United States citizens and another 41% of the students were non-Caucasian. The majority of the students were Asian. The average values for SAT scores, when grouped by citizenship and ethnicity, reveal that the majority of foreign and non-Caucasian students had MSAT scores 100 ooints or more over their VSAT scores (See Tables 2 and.3,. It seems likely, chcrefore, that first laneuaee differences would exolain the slirhtlv neaative correl&on between VSAT sEores and fikalcourse grade. In Table 2, the higher final grades of foreign students, 92% of whom were Asian, when compared to the grades of U S . non-Caucasian students, 77% of whom were Asian, may be the result of the foreign students solving more problems and their possessing cultural values that empha-

size a greater dedication to learning (4). The lower MSAT scores of the U.S. Caucasian students make it more difficult to compare them to the two previous groups. Conclusion The regression model presented here, aiter accounting for varying mathematical and verbal abilities, demonstrates that increased workshop attendance is associated with higher final course grades for workshop students. This grade improvement is independent of varying degrees of motivation as measured in this analysis. These results are consistent with those of Turner ( I ) and St. John (3). This study, however, is the first analysis to (1) select only for students who had attended at least one workshop session (2) analyze those students' mathematical and verbal abilities as measured by their SAT scores,and (3) attempt to use a measure of motivation.

It is dimcult to say why Deal's study (2) did not yield similar results. Deal reported that grade improvement by workshop students was statistically insignificant. However, he had a small sample size and did not discuss the nature of the offeredworkshop. Nevertheless, he acknowledged that grade improvement might be significant if those workshops were more extensive. Unfortunately, he did not discuss the number of workshop sessions attended by each student. Although student perceptions of the average number of hours per week spent solving problems and reading seems a reasunable measure of m o ~ ~ a t i osuch n , perceptio& were not significant predictors of final course made. Even if the reported hours were monitored more rigo~ously,there may not necessarily be a linear relationship consistent with the variables which fit the equation. Furthermore, it may be impossible to separate out the motivation variable. In the final analysis, workshop attendance itself may be a measure of motivation. This would not preclude the actual benefits of attendance, as so oiten expressed by students in their evaluations of the workshops a t U. C. Davis. Acknowledgment I wish to thank the following people of the University of California, Davis: Timothy Donnelly of the Department of Chemistry for providing the total points earned by each student; Peter Rock of the Department of Chemistry,Jerry Knutson of the Deoartment of Aericultural Eneineering and dim Dykes of tke ~e~artmen;ofStntistics fir critic2 discussions: Midge Clinton of the Learning Slulls Center for helping eolleci and process the data; viFginia Martucci of the Learning Skills Center for helpful discussions; and Gary Perkins of the EOPISAA Information Office for arranging for student advising counselors to help with telephone surveys. Literature Cited 1. Turner, K E.J Chem. Edw. 1880.67.954-957, 2. Desl, W.J. J Coll. Sci. k h . 1984, 1.3, 15P156. 3. St. John, E. vnpubliahed paper Academic Suppart Se-ces,

U. C., Imine. 1989; p

1-14.

4. Caplan, N.: Choy, M. H.: Whitmore, J. K Sci Amor. 1992,266(2),3642

Volume 70 Number 12 December 1993

1015