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1 : sam 2 #!/usr/bin/perl -w
2 :     #Construct for matching list.
3 :     #Inherits from List.pm
4 :     #VS 6/16/2000
5 :    
6 :     =head1 NAME
7 :    
8 :     Match.pm -- sub-class of List that implements a matching list.
9 :    
10 :     All items accessed by $out = $ml -> item( $in );
11 :    
12 :     =head1 SYNOPSIS
13 :    
14 :     Match.pm is intended to be used to create standard matching questions in which the the student is given a list of questions and a list of answers and is asked to match the correct answers to those questions. Some answers may be used more than once while others are not used at all. The order of answers is usually random but some answers can be appended to the end of the list in a set order (i.e. 'None of the above', 'All of the above'). Answers are not directly typed in but are given a corresponding letter that is the answer that the system expects. (i.e. 'the answer to #1 is A' not 'the answer to #1 is the square root of 2'). Also, students can be given different sets of questions (to avoid students sharing answers) by entering many questions and then using choose with a number less than the total so that each student only receive a sub-set of those questions.
15 :    
16 :     =head1 DESCRIPTION
17 :    
18 :     =head2 Variables and methods available to Match
19 :    
20 :     =head3 Variables
21 :    
22 :     questions # array of questions as entered using qa()
23 :     answers # array of answers as entered using qa()
24 :     extras # array of extras as entered using extra()
25 :    
26 :     selected_q # randomly selected subset of "questions"
27 :     selected_a # the answers for the selected questions
28 :     selected_e # randomly selected subset of "extras"
29 :    
30 :     ans_rule_len # determines the length of the answer blanks
31 :     # default is 4
32 :    
33 :     slice # index used to select specific questions
34 :     shuffle # permutation array which can be applied to slice
35 :     # to shuffle the answers
36 :    
37 :     inverted_shuffle # the inverse permutation array
38 :    
39 :     rf_print_q # reference to any subroutine which should
40 :     # take ($self, @questions) as parameters and
41 :     # output the questions in a formatted string.
42 :     # If you want to change the way questions are
43 :     # printed, write your own print method and set
44 :     # this equal to a reference to to that method
45 :     # (i.e. $sl->rf_print_q = ~~&printing_routine_q)
46 :    
47 :     rf_print_a # reference to any subroutine which should
48 :     # take ($self, @answers) as parameters and
49 :     # output the answers in a formatted string.
50 :     # If you want to change the way answers are
51 :     # printed, write your own print method and set
52 :     # this equal to a reference to to that method
53 :     # (i.e. $sl->rf_print_a = ~~&printing_routine_a)
54 :    
55 :     =head3 Methods
56 :    
57 :     qa( array ) # accepts an array of strings which can be used
58 :     # for questions and answers
59 :    
60 :     extra( array ) # accepts an array of strings which can be used
61 :     # as extra answers
62 :    
63 :     print_q # yields a formatted string of question to be
64 :     # matched with answer blanks
65 :     print_a # yields a formatted string of answers
66 :    
67 :     choose([3, 4], 1) # chooses questions indexed 3 and 4 and one other
68 :     # randomly
69 :     choose_extra([3, 4], 1) # choooses extra answers indexed 3 and 4 and one
70 :     # other
71 :     makeLast( array ) # accepts an array of strings (like qa) which will
72 :     # be forced to the end of the list of answers.
73 :    
74 :     ra_correct_ans # outputs a reference to the array of correct answers
75 :    
76 :     =head2 Usage
77 :    
78 :     Create a match list using the new_match_list call.
79 :    
80 :     =for html
81 :     <PRE>
82 :     <I>$ml = new_match_list</I></PRE>
83 :    
84 :     Use qa() first to enter questions and answers in alternating pairs. Note that
85 :     multiple questions can have the same answer. Any duplicates will be eliminated.
86 :    
87 :     =for html
88 :     <PRE>
89 :     <I>$ml->qa(
90 :     '\( x^2 \)',
91 :     'quadratic',
92 :     '\( x^3 \)',
93 :     'cubic',
94 :     '\( x^3/x \)',
95 :     'quadratic',
96 :     '\( log(x) \)',
97 :     'logarithmic',
98 :     '\( 2^x \)',
99 :     'None of the above',
100 :     );</I></PRE>
101 :    
102 :     After you call qa you can use extra() to enter extra 'answers'. Again all
103 :     duplicates will be eliminated.
104 :    
105 :     =for html
106 :     <PRE>
107 :     <I>$ml->extra(
108 :     'linear',
109 :     'quartic',
110 :     'really curvy',
111 :     );</I></PRE>
112 :    
113 :     After calling extra you can use choose to select which questions and/or how many each student sees. This helps give students different sub-sets of the full question set so that students cannot cheat as easily. A list of numbers in brackets indicates which questions every student sees (counting starts with 0) and the final number outside of brackets is how many more questions should be randomly picked for each student. Though it is available, the use of selecting specific extra answers is not recommended for novices as the indexing is complicated (see below).
114 :    
115 :     =for html
116 :     <PRE>
117 :     <I>$ml->choose([0], 1);</I></PRE>
118 :    
119 :     would show the first question and a random question while
120 :    
121 :     =for html
122 :     <PRE>
123 :     <I>$ml->choose(3);</I></PRE>
124 :    
125 :     would show 3 random questions (but never call choose more than once).
126 :    
127 :     After calling choose, use choose_extra to select which of the extra 'answers'
128 :     will be given to each student. Note that unused answers are dumped into the
129 :     list of extra 'answers' so the indexing may be difficult to grasp at first.
130 :     (This can be stopped by doing the following: $ml->dumpExtra = "";)
131 :    
132 :     =for html
133 :     <PRE>
134 :     <I>$ml->choose_extra([0], 2);</I></PRE>
135 :    
136 :     would show 3 extra answers besides the correct one note that these extra
137 :     answers may consist of answers from the questions that were not used.
138 :    
139 :     After calling choose_extra you can use makeLast to add specific answers to the
140 :     end of the list of answers or to force already existing answers to be moved to
141 :     the end of the list. This is usually done for 'None of the above', or 'All of
142 :     the above' type answers.
143 :    
144 :     =for html
145 :     <PRE>
146 :     <I>$ml->makeLast(
147 :     'All of the above',
148 :     'None of the above'
149 :     );</I></PRE>
150 :    
151 :     If you want you can change the size of the answer boxes at any time (the default is 4).
152 :    
153 :     =for html
154 :     <PRE>
155 : gage 160 <I>$ml->ans_rule_len(10);</I></PRE>
156 : sam 2
157 :     Now you would start your problem with a BEGIN_TEXT tag and print the questions
158 :     and answers with the print_q() and print_a() commands. Within the
159 :     BEGIN_TEXT/END_TEXT block, all calls to objects must be enclosed in \( \).
160 :     (The $PAR start a new paragraph by printing a blank line).
161 :    
162 :     =for html
163 :     <PRE>
164 :     <I>BEGIN_TEXT
165 :     $PAR
166 :     \{ $ml->print_q() \}
167 :     $PAR
168 :     \{ $ml->print_a() \}
169 :     END_TEXT</I></PRE>
170 :    
171 :     Now all that's left is sending the students answers to the answer evaluator
172 :     along with the correct answers so that the students answers can be checked and
173 :     a score can be given. This is done using ANS, an answer evaluator and the
174 :     ra_correct_ans variable.
175 :    
176 :     =for html
177 :     <PRE>
178 :     <I>ANS(str_cmp($ml->ra_correct_ans));</I></PRE>
179 :    
180 :     =cut
181 :    
182 :     BEGIN {
183 :     be_strict();
184 :     }
185 :    
186 : gage 160
187 : sam 2 package Match;
188 :    
189 :     @Match::ISA = qw( List );
190 :    
191 :     # *** Subroutines which overload List.pm ***
192 :    
193 :     #sends letters for comparison instead of actual answers
194 :     sub ra_correct_ans {
195 :     my $self = shift;
196 :     my @ans = &List::ALPHABET( @{$self->{inverted_shuffle}} );
197 :     \@ans;
198 :     }
199 :    
200 :     1;

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