[[PageOutline]] = Bolt reference manual = A Bolt course consists of: * '''Lessons''': any web-based teaching material * '''Exercises''', used for reinforcement and/or assessment. * A '''course document''' describing the order in which lessons and exercises are shown. == Lessons == A '''Lesson''' contains instructional material. It may be either an HTML file or PHP script. It may contain embedded audio, video, Flash, or any other content. Some restrictions: * It shouldn't contain enclosing or tags (Bolt will supply these, as well as navigational header and footer). * It shouldn't contain any hyperlinks (Bolt will supply navigational links). If a lesson is implemented as a PHP script, information about the student is available to it in a global variable $student, This information may be used to customize the page. The available information is: {{{ $student.sex; // 0=unknown, 1=male, 2=female $student.birth_year; $student.country; $student.name; $student.bandwidth; // 1: <100Kb; 2: <1Mb; 3: <10Mb etc. $student.has_audio_output; // 1: no, 2: yes $student.has_audio_input; }}} For example, suppose you want to use a larger font for students over 50: {{{ if ($student.age > 50) { echo " "; } }}} An alternative way to vary content based on student attributes is to use separate lesson files, selected in the course document. == Exercises == Exercises are PHP scripts that call Bolt API functions. Here's an example consisting of a multiple-choice question: {{{ }}} The correct choice is the first element of the array. Each time the question is shown, the choices are presented in a random order. Here's an example that shows an image; a correct answer is a click in the indicated subrectangle. {{{ "; bolt_image_rect( 'dog.jpg', array(100, 60, 110, 70) ); ?> }}} Bolt supplies functions for other types of questions, such as inclusive multiple-choice and fill-in-the-blank. An exercise can include multiple questions. == Course documents == The structure of a Bolt course is defined by a PHP script called a '''course document'''. The script calls Bolt API functions to create a hierarchy of "units" of two types: * '''Basic units''': lessons and exercises * '''Control structures''' representing sets of units, together with rules the govern their use. The function '''lesson()''' specifies a lesson. For example, the following course consists of a single lesson: {{{ }}} The parameters of the lesson are: || name || the "logical name", used as an internal identifier but not visible to students; see "Names and state" below || || title || a name shown to students || || filename || the file containing lesson content || || reading_level, detail_level || optional attributes of the lesson || Similarly, '''exercise()''' specifies an exercise: {{{ }}} There are various control structures; see below. The simples one is a 'sequence', which specifies a set of units that are shown in sequence. Here's an example of a course with two lessons followed by an exercise: {{{ }}} == Changing course documents == Course documents need not be static. You can change them whenever you want (that's the point of Bolt). What happens if a course changes while students are in the middle of it? The general answer is the Bolt recovers as gracefully as possible. For each student, Bolt maintains a "course state" - a set of data, for each control structure that the student has visited in the course, describing the student's "position" in that control structure. When a student clicks the Next button, or resumes the course after an interval, Bolt uses the course state to decide what item to display next. For example, suppose your course has a sequence with 3 elements, with logical names (red, yellow, blue). and a student is on the third. The course state for the sequence consists of two items: (blue, 2). 'blue' is the logical name of the third element, and the index number 2 (indicates that the student has completed 2 units in the sequence). If the student resumes the course, Bolt will find their place in the sequence first by looking up the logical name; if it is not found, then it will use the index number. For example: * If you change the sequence to (red, blue, green, yellow) then the student will be shown the units blue, green, and yellow. * If you change the sequence to (red, yellow, green) then the student will be shown the unit 'green'. * If you change the sequence to (red, yellow) then the student will have finished the sequence. == Nesting and functions == Control structures may be nested. For example: {{{ sequence( name("x"); lesson(...), sequence( name("y"), lesson(...), exercise(...) ) ); }}} You can also use PHP functions as a way of organizing course structure: {{{ function my_unit() { return sequence( name("y"), lesson(...), exercise(...) ) } sequence( name("x"), lesson(...), my_unit() ); }}} == Names and state == In general, units must have unique logical names. However, two units may have the same logical name if they are identical. For example: {{{ function my_unit() { return random( name("y"), lesson(...), lesson(...) ) } return sequence( name("x"), my_unit(), exercise_set( name("z"), exercise(...), review(.5, my_unit()) ) ); }}} This specifies a course in which my_unit() is displayed, then an exercise is given. If the student scores below .5 on the exercise, he is shown my_unit() again and the exercise is repeated. So there are two units with logical name 'y' in this course, but they are identical, so this is allowed. When there are multiple units with the same logical name, they share a single state. == Control structures == === Sequences === Sequences were described above. === Random === The '''random''' control structure selects randomly from a set of units. {{{ }}} === Select === The '''select''' structure takes a set of units and a 'valuator' function. The valuator function returns the 'value' (i.e. the likely benefit) of showing the unit to the student. The unit for which this value is greatest is shown. {{{ verbal_level - $unit->verbal_level); } return select( name('course'), valuator('value'), lesson( name('lesson 1'), filename('bolt_sample_lesson1.php') ), lesson( name('lesson 2'), filename('bolt_sample_lesson2.php') ), ); ?> }}} === Exercise set === The 'exercise_set' structure specifies a set of exercises and a value 'num_to_show'. This number of exercises is chosen randomly and administered. {{{ exercise_set( name('exer_set'), num_to_show(1), exercise( name('exercise 1'), filename('file_1.php') ), exercise( name('exercise 1'), filename('file_1.php') ), review(.3, basic_review()), review(.7, int_review()), refresh(array(7,14,28)) ); }}} == Review == Optionally, one or more '''review''' attributes can be given. Each specifies a grade threshold X and a list of review units. If the student's grade on the exercise set is less than some Y, == Memory refresh ==