Jesse H. Day ond Clifford C. HOUL
Ohio University Athens, Ohio 45701
Student Paced Learning An experiment in teaching large
The need for improved teaching in general chemistry has been long recognized. Most efforts, such as those of the Advisory Council on College Chemistry, or those reported by individuals at sessions of the Division of Chemical Education or in THEJOURNAL OF CHEMICAL EDUCATION, have centered attention on the content and structure of the course or on the use of various audio-visual aids. None has approached what we believe to be a central problem: to provide independent instruction with maximum freedom in spite of large classes. Students are individuals with different abilities, backgrounds, interests, and motivations. The experimental course described in this paper attempts to provide each student with individualized instruction without extraordinary demands on the instructor's time. Most efforts in this direction are defeated by the built-in rigidities of large class size and scheduling problems so that teaching becomes the prisoner of logistics. Our approach has been to offer the student all possible types of help in the attainment of very explicitly stated objectives and let him proceed at his own pace to meet those objectives. He can work completely independently, or with the use of any or all forms of the supporting help provided. I n short, much necessary activity focuses on decisions that are made by the teacher; what material to cover and methods of presentation. The experimental course focuses additionally on the decisions to he made by the student; the preferred method of presentation and the time of encounter. The experimental course is based on complete freedom for the student. I t does not matter when or how, or from what sources a student learns, all possible sources are provided, but the path is chosen by the student. He is even free t o select the completely rigid conventional class instead of the experimental program. The Plon of the Course Statement of Obiectives
The most important single factor in this course is the detailed outline of what the student must know (be able to do) in order to pass the course. This is in fact the central point of difficulty for any student in any course he ever takes. Does he have to know everything in the text, or just be able to work the problems at the end of each chapter? Will he be called on to explain, or simply t o do? Should he rely for guidance on the stresses put by the lecturer on lecture material? Is it safe to ignore what the Presented in part before the Division of Chemical Education at the ACS Meeting in IMinnertpolis, April, 1969.
C~CYSS~S
lecturer doesn't mention? What specific facts need to be committed to memory? What kind of examination will be given? It matters a good deal whether a true-false or an essay test is to be used. Perhaps this should not be true, but it is, and it engages a good deal of student thought. . The simple and discouraging fact is that most teachers never do have a clear statement of what the student must be able to do to earn a particular grade or even pass. Most instructors assume that the text itself is sufficient as a statement of objectives. This assumption is not a valid one except for properly "programmed" material. A clear statement of objectives should always be worked out. Even if the instructor did it only for himself, it would do a great deal to clear his head for the preparation of valid examinations and realistic grading. Oddly, in some courses the main battle seems to be between the students, wondering what they are supposed to know, and the instructor trying to keep from telling them. The defenses are ingenious, "I am trying to teach understanding" is frequent, especially from the teacher who never tried t o define the word. We decided on an operational definition-"if the student can work the problems and answer the questions, he has sufficient understanding to undertake the next course." For these reasons a statement of objectives was first prepared which told the student what he must be able to do to pass the final examination. It is much easier to speak of a clear statement of objectives than it is to prepare them. The fact that a perfect statement from each instructor in the world would almost certainly be unique can be safely ignored, but the question "how detailed must the statement he to be 'clear'?" is a tough one. If the statements are too detailed, the list of objectives becomes a mere summary or condensation of the textbook. If the statements are too broad or general they become meaningless. We tried to write statements that would be of maximum help to the students, neither too narrow nor too wide. The reader may make his own judgment of our success by reading the sample page here reproduced (see Appendix I) and typical examination questions on that chapter (see Appendix 11). Study Materials and the Class Library
The student has a standard textbook for the course. He is introduced to the Class Library, housed in a study room to itself. This library contains multiple copies of several kinds of self-study material, such as (a) programmed texts in chemistry, algebra, and logarithms; (b) the various paperback senes of chemistry texts on special or individual topics; (c) audio Volume 47, Number 9, September 1970
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and video tapes of the lectures for students who wish to hear or rehear a particular lecture; (d) other standard chemistry texts; (e) some journals, such as Science, Chemistry, THE JOURNAL of CHEMICAL EDUCATION and Chemical and Engineering News. It also contains comprehensive sets of examination questions accurately representative of the final examinations, sorted as to topic (such as chapter coverage in the textbook being used in the course). We saw no point in keeping i t a secret from the student as to what he was supposed to learn. The library was in charge of a student librarian. All possible material was available for overnight and weekend check out. Lectures
The student is given a list of some 30 lectures given during each quarter, with each topic at a scheduled date. Attendance is optional. A student who is expert with oxidation-reduction reactions, for example, would be wasting his time attending lectures on this topic. He would do betterto spend the,time studying a topic he is not familiar wlth and avold the boredom of hearing old stuff. Careful clarification of material for the average or slower student is a sure way to lose the brighter student's interest in the whole course. Yet such clarification is available for all who need or want it under this optional-attendance, scheduledlecture plan. A potential special gain in the scheduled lecture is the better structuring of lectures. Since the stated tooic must be covered in the 50-min ~ e r i o d there , is nd time for wandering or leaving a-subject partly covered to be continued next period. Tutorial Help
One of the greatest alleged weaknesses of the lecture system is the inability of the individual student to ask the relevant question at the time he needs the answer and recognizes the need. The use of discussion sessions is only partly a remedy since even in small discussion sessions the same three or four students ask all the questions. To require attendance at such sessions for all students regardless of need or participation is well calculated to increase aversive reaction t o the subject. To provide more individual attention there was, during the first year of this course, a "course office," open at least 20 hr a week, staffed by thirdand fourth-year graduate students. The student could go there t o find individual attention for the precise difficulties he needed help on. The lecturer for the course also made himself available on a regular schedule.
We see no virtue in the usual system, where the student carries the record of every failure, like an albatross around his neck, bearing forever the stigmata of presumptive stupidity, when the reason for failure could have been any of a thousand perfectly legitimate reasons. Preparation of the examinations wab done carefully to reflect fairly and fully the scope and intent of the course's statement of objectives. We did not give the same examination over but each examination covered the same material and was as nearly as possible of the same difficulty. The students were selected for this experimental course by their own choice. At the time of registration for General Chemistry, each student received a description of the course and then chose between it and the conventional course. Discussion
Three kinds of assessments can be made of the program. First, a comparison of what we hoped for with what actually occurred; second, the evaluation by the students; third, a statistical analysis of student achievement as compared with a control class. Student response came from personal interviews and evaluation forms completed a t the close of the quarter or when he decided to accept the grade achieved. I n making our own assessment it was necessary to look back to the original considerations which led us t o make the experiment in the first place. There has always been discussion along the lines of, "If we do this, the student will do that" or "Students must be forced to do certain things or they won't do anthing" and so on. Let the reader supply his own further examples. What we found disturbing is that such talk assumes something about the nature of "students" who are in fact a uniquely miscellaneous collection; we wanted to turn them loose and record what their behavior is in fact when there are no restraints and limitless opportunity. (Well, almost limitless.) So, while we tried to make no assumptions about the nature of students, we did have a weather eye on some often repeated statements found in the literature of learning theory, such as the following
The Exomirntion
A common complaint of the student is that he is sn IBM number, hedged by rules more appropriate to children. To give him responsibility is to hasten maturity. . .. To allow the possibility of success without the hazard of penalty for failure is to remove most of the aversive reaction to oonventional classroom situations where behavior control is almost totslly sversive. A failed student rarely fails all of s course. He may in fact actually have learned more than the bright student who came into the course already knowing 90% of the subject.
A h a 1 examination for the course was offered four times during each quarter. The first time was after one week of classes and approximately every three. weeks thereafter. When the student felt ready to take the final examination, he did so. If he passed, he received the appropriate grade. If he wished to improve the grade, he could study some more and take a later examination. If at the close of the quarter he was still dissatisfied with his mark he had a fifth and h a 1 opportunity the first day of classes the following quarter to improve the grade. The grade in the course was that of the last examination taken.
What actually happened was that attendance in the experimental section was not much different from that in the regular section. We did not see anyone running about shouting "Free at last!" The tutors went unused. Supplementary printed material was scarcely bothered. . Some of this might have been expected, since students have had at least 12 years conditioning in their response to the school room, and they are as much creatures of habit as anyone. And we realized further that the freedom in the course could hardly seem exceptional in a school where attendance is rarely (read never) taken, the pass-fail
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option is open, and which next year will try out the system of giving only A, B, and C grades (the F's are forgotten, and the D's a matter of student option). On the positive side, student response to the "Study Guide" with its brief resume of each chapter and statements of "What You Should Be Able To Do" was highly prized by a large majority of the students as were the sets of examination questions kept on file in the class library. The audio and video tapes of the lecture were well used. We were fortunate to have the necessary videotape equipment on loan from the Advisory Council on College Chemistry (ACa) for this experiment. We deliberately taped the lectures for those students who missed a lecture due t o illness or other reason and did not wish t o rely on someone else's notes or conversation with the lecturer. As it turned out the tapes were used by these very students and hence are considered a very successful part of the course. During the winter quarter one of the students could not schedule the experimental section because of a time conflict with another class but he wanted this approach very much, so arrangements were made for him t o register for the experimental section and see the lectures by videotape at an hour convenient to him, and he earned an A for the quarter. Several students with extended illnesses, family prohlems, etc., used the audiotapes to bring themselves up-to-date when they did return to classes. These students were very appreciative of this opportunity. One of us (C. C. H.) intends to continue the use of the audio tapes as a regular part of his lectures. Almost one-third of the students finished early; certainly this had advantages for both student and instructor; hut another one-third chose to take the fifth examination to improve their grades. Probably the greatest surprise was the fact that the students failed to utilize the tutors that were available to them. We did everything we could think of to get the students to use their services, hut the response was extremely poor in terms of number of student visits and number of different students seeking help. It seems that the student who chose this course was totally willing to "get it" on his own with as little human assistance as possible. During the autumn quarter the experimental class had the opportunity to work in the laboratory for a 4 h r period of time compared to only 2 hr a week for the regular class. This was intended to give them the opportunity to complete the laboratory work early as well. We found, however, that they tended to use more time to complete a single experiment than try t o do two experiments in a given lab period, so that option was dropped and they were held to the same laboratory schedule as the regular section winter and spring quarters. Probably the best way to make the laboratory operate on the same principle and philosophy as the lecture would be to have the laboratories open a fixed number of hours per week and leave it to the student to complete the experiment any time within those hours without scheduling a specific 2 or 3-hr block of time each week as is done at Simon-Fraser University, British Columbia. Group Analyses
Analysis qf variance tests were run to determine if there were any differences between the experimental
group and the regular section taught by C. C. H. The variahles were ACT or SAT scores (whichever was available), high school or previous university accumulative average, years of high school chemistry, high school population, years of high school mathematics, and the grade received in the course. For discussion purposes the variahles used with the ACT group will be identified as: (1) ACT English, (2) ACT Math, (3) ACT-Social Science, (4) ACT Natural Science, (5) ACT Comprehensive, (6) high school size, (7) previous cumulative average, (8) years of high school chemistry, (9) years of high school math, (10) grade received in the course. The SAT group variahles will be identified as: (1) SAT verbal, (2) SAT math, (3) high school population, (4) previous accumulative average, (5) years of high school chemistry, (6) years high school math, and (7) course grade. Significance differences' were noted between the classes in these areas: ACT Social Science, Natural Science, and Comprehensive scores; previous accumulative average; years of high school chemistry; and course grade. Of particular interest are the differences between previous accumulative average and course grade that indicate the experimental group came with alower average but attained a significantly higher grade than the control group which was "smarter" to begin with. It was obvious too that the number of years of high school chemistry may he an important factor in determining "success" in General Chemistry a t Ohio Unvenity since the experimental group had considerably more high school chemistry experience. To determine if "success" could be predicted by any one variable or combination of variahles simple and multiple product-moment correlation coefficients (R) were calculated. Of interest were those variahles whose coefficients are the highest when correlated with the course grade. The experimental SAT group had the highest correlation with variahle 4 (0.269) and variable 1 (0.268). The same was true with the control group hut they were larger, 0.474 and 0.331, respectively. The results are not surprising because historically these variables have been the best "predictors" of success in college of university work. If all the variahles for the SAT groups are used in corn-, hination the multiple R reaches 0.324 for the experimental group and 0.506 for the control group. It appears the control group was the more predictable one. Further analyses were made to determine which variahle would make the most significant contribution to R, in which order the variahles should be added to a prediction equation, and when further addition of variables fails to significantly improve R. It was found that the order for the experimental section was 4, 1, 6, 2, 5, 3 hut any addition beyond variable 4 did not significantly improve R. The order for the control group was 4, 2, 1, 6, 3, 5 but addition beyond variable 2 was insignificant. It was interesting to note that in both groups variahle 5 had low single R values with course grade and fell well down the list in importance to the multiple R value. I t is also interesting to note that variahle 3 did not show a great positive correlation with any of the other variables. With the ACT groups variahle 7 has the highest 1
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single R (0.363) followed by 2 (0.347) and 9 (0.340) for the experimental group. However, the control group has the highest R with variahle 5 (0.489) followed by 2 (0.467), 4 (0.428) and 3 (0.426). The experimental group with all ten variahles included attained a multiple R of 0.508 and an order of addition of 7 , 9, 1, 2, 6, 5 (addition of other variables failed to increase R ) however, addition beyond variahle 9 proved to he insignificant. Even though variahle 2 had the second highest single R with variahle 10 i t did not contribute significantly to the prediction equation. The multiple R for the control group was 0.563 with an addition order of 5 , 1, 7, 6, 8 , 4, 2 which was quite different than the experimental group. The experimental ACT group on paper appeared to he the "superior" group yet the single R values for this group show poorer correlation with course grade than those in the ACT control group. Is the control group again the more predictable? Why should a variahle as ACT English with a low single R contribute so greatly to the multiple R for the control group and rank third for the experimental group multiple R when it has a negative single R? Grade distribution indicated there was no significant difference between the classes in the autumn quarter, although the regular class had a larger percentage in the C and D ranges. Winter and spring quarter grades went up in both sections, hut the experimental section had a considerably larger advance during the winter quarter as shown by the table. Winter Quarter G r a d e Distribution
Experimental section (%of tot,alenrollment) Regular section
What Next
The course is being offered again during the 1969-70 academic year. Some changes are being made in the study guide, and the tutoring service has been eliminated due to a number of circumstances, hut basically because of the lack of student response and an anticipated manpower shortage in the form of graduate teaching assistants. It seems evident from the results, interviews, etc., that the students on the whole could read and comprehend this material placed in their hands, so we intend to have fewer "formal" lectures and incorporate many more demonstrations to illustrate and/or re-enforce concepts mentioned in the text or introduced in the laboratory. The videotape equipment has been passed on to Purdue University so we are unable to videotape the lectures this year. To provide the students with the opportunity to ask questions they are "afraid" to ask in a large lecture class or even a small recitation section an "electronic secretary" has been installed on the phone of C. C. H. The students may then call his office (particularly during the evening hours) and ask to have a specific problem or concept explained that they may he having difficulty with. They may then he answered during lecture and/or he discussed in their recitation sections. 632
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The data presented represent the complete 1968-69 academic year. During the 1969-70 year the same calculations will. be made for each quarter and collectively a t the close of the year to see if any differences appear between the two years or from quarter to quarter. What is needed is a series of courses which can he completed early, hut in our case the student merely had either more leisure time or more time to study other courses. So while the possible early finish each quarter does not break the lock-step, it probably does relieve some of the chafing. In all this we see justification for two propositions; a statement of objectives is welcomed, and there are students who will finish early if permitted. I t is our problem how to provide further opportunity for the early finishen. We are grateful to the ESSO Educational Foundation for the original funding of the experiment and to the Ohio University Department of Chemistry for support of the second year of the experiment. We thank Dr. Charles Harrington of Ohio University for his assistance and consultation concerning the product-moment correlation calculations and Mr. David McQuate for preparing the data for computation and completing the analysis of variance calculations. Tables of the variance analysis and correlation coefficient calculations are available upon request. ~ ~ ~ e n I:d Sample i x Statement of Objectives What You Should Be Able t o Do When YouHava Learned Chapter 24 1. Write correct definitions of t h e worda and phrases Bated under New
Terms and illustrate eaoh definition with one or more mamples. 2. w r i t e the electron structure of each of the halogens. 3. State the form in whioh each of the elements ocoura naturally and where i t can be found. 4. Write ahemical equation8 for the reaction of eaoh of the halogens with water. 5. Write chemical equations for t h e folloaing renotions Chlorine with aulfur dioxide: with ethylene; with carbon monoxide Chlorine with bromide ion; with iodide ion Bromine with iodide ion HBr with sulfuric mid 6. w r i t e ohemioal squations for the reaction of eaoh of t h e halogens with hydrogen. 7. State t h e ways in which H F isdiflerent from t h e other hydrogen halides. 8. Write chemical equations for the preparation of each of the hydrogen halides .--.irnm t h d r salts. -~~~ 9. state the groups of elements with whioh the halogens form; 1. ionic honda. 2. partly covalent bonds, and 3. covalent bonds. 10. Describe briefly the means of production of eaoh of t h e halogens. 11. Give one (or two if possible) important "sea for eaah of the following suhstanoes ~~
~
~
fluorine chlorine HF HCL KC1 ethylene dihmmide
Appendix 11:
bromine CaF,
iodine AgBr
Typical Exam Questions
N s and CI- are isoelectronic species? T F The most oommon oxidation state of t h e halogens ia -. , but on oooasion they exhibit a maximum of --. The free hslosans &at as diatomic molecules t h a t are (polar, nonpolar). Ans. The hydrogen halides are all (gases, liquids. solids) a t normal room conditims. Aria. Indicate whether the follovina reactionsare correct in terms of oroduots (none of the equations a& balanced). a. FI H O = HF 01 T T F h. Clr 4 HIO m HCL . HClO T F c. I;+ B& = I, BrT F d. HBr KOH KBr HOH T F e. HCI Mg = MpCIs HI T F f. N a I HISOI = H I NanBOr T F Match the items t o the left with t h e item from the right hand list thht bed describes t h e item t o the left. --I C l A. cation AgBW B. dimovered chlorine -Sohee1a C. used as a good reducing agent HCI(I) D. interhalogen E. used t o etch glass -- HFts) 11 F. important in photographic emulaione F a - v . discovered bromine
-.
+
+ + +
---
+
-
+ +
+ + +
~~
H. I. J. K.
complex ion fuel additive used t o olean metal aurfhces, motar, etc. in aloohol solution becomes a poweriu1 diainfectant L. used t o produce chlorine pas commercially What are t h e products when a brine solution (NaCI) ia electrolyeed?
4"s. -
Which of these gases would diffuse more rapidly than the others? NHa b) HCL e) He d ) 0, Ana.-Which of these compounds ia an interhalogen? a) HCL b) XeFa c) BaCh d) ICI e) FB Anr.Circle the element or compound t h a t has t h e largest (higheat): Fa, Cb, Bra. I* Melting point: Ionic Radius: F-. CI-. Br-. I Boiling Point: H F , HCI, HBr. H I Oxidiring Power: Fs, Cli, Bn,b a)
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