An Interactive Program for Teaching pH and Logarithms When introducing undergraduates, particularly a t the freshmen level, to the concept of pH it is often found necesssry to reinforce and improve their background in logarithms. Instead of spending valuable cltmroom time discussing logarithmz, we decided to develop an interactive program to attempt to bring all the students to the same level of proficiency and t o demonstrate a unique CAI approach. The program, which is written in APL, can be accessed through any one of the more than one hundred IBM 2741 remote terminals which are connected t o the University's central IBM 370-155 computer. Students who wish to use i t only need to know how tosign on and retrieve the program from thepubliolibrary. The CAI program issubdivided intosixteen interrelated and interdependent parts whichinclude topics such as the use of tables. the use of loearithms in findine Dowers and roots., nH. . . and intemolations t o mention a few. The eomputer adjustsitself to theetudent'srsteof progress by requiring two successive correct answers before moving on to the next unit. Within a given unit the basic format of the question is the same; however, since each number in an erample is randomly generated each question is differentregardless of how many times i t is repeated. The student has nine special control words a t his disposal. Far example, the ward SKIP enables him t o skip the units he feels competent with and allows him to spend more time on new material. If he feels the need for more drill in a given segment, the word REVIEW allows him to back track to another unit. CALCULATIONS enables the student to use the computer as a desk top caloulrttor while EXAMPLE enables him to see the anewer and request an dditional example on the current material. INFORMATION gives a step-by-step solution to a problem similar t o the one the student is working on. The word STOP allows thestudent to stop the program and leave the terminal any time he wishes t o do so. The next time he signs on to continue the program the compnter resumes the progrsm with the same question under oonsideration a t the time the STOP command was executed. We will be glad t o send copies of this program or of an improved version making full use of the APLPLUS file subsystem tointerested persons.
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Volume 49, Number 8 , August 1972
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