This chapter will acquaint you with additional features of TUTOR and PLATO. See Appendix A for sources of additional information.

We have emphasized the keyboard and plasma display panel as the main input and output devices used in communicating with the student. Other devices which may be used include a projector of color photographs, a touch panel, a random-access audio playback device, and other specialized input-output devices. All of these terminal-associated devices are easily managed by TUTOR.

The plasma display panel is flat and transparent, which makes it possible to project photographs on the back, superimposing color photographs with plasma-panel text and line drawings. There exists a microfiche projector for the PLATO terminal which will project any of 256 color photos, with fractional-second access time to any of these 256 pictures. (A “microfiche” is a sheet of film carrying many tiny pictures.) Microfiches can be made from a set of ordinary 35mm slides. Students or teachers can insert the appropriate microfiche in the terminal for the subject to be studied. The -slide- command selects any of the 256 photos: “slide 173” will project the 173rd photo. Additional options on the -slide- command permit the independent control of a shutter in the projector.

The touch panel is a device which puts a grid of 16 vertical and 16 horizontal infrared light beams just in front of the plasma panel. When a student points at the panel, he breaks a horizontal and vertical beam. The information as to which beams were broken is sent to the computer as a “key” and the lesson can use this information to move a cursor, choose a topic pointed at, etc.

We discussed in Chapter 8 how to know where the student touched the screen. Another way is to use the information in the system variable “key”, which contains the last “key” input from the student, whether it came from the keyboard, the touch panel, or some other external input device. Here is a unit which will analyze the inputs:

The -enable- command permits touch inputs as well as inputs from any device connected to the external input connector at the back of the PLATO terminal. (The external input device might be a temperature sensor, an analog-to-digital converter, etc.) Without an -enable- command these inputs are ignored. A -disable- command will also cause inputs to be ignored. The system variable “key” contains a 10-bit integer (see the section on bit manipulations in Chapter 9): the most significant or left-most two bits identify the source of the key (0 for keyset, 1 for touch panel, 2 for external input), and the least significant or right-most eight bits contain the actual data (which keyset button, which touch panel beams, what external data). In the case of the touch panel, the eight data bits contain four bits of x and four bits of y to specify a position. A succession of external inputs can also be retrieved with a single -collect- command.

If an -enable- command is placed just after an -arrow-, touch inputs can be accepted. There is a -touch- judging command whose tag specifies a screen location (and optionally a spatial tolerance). The -or- command is particularly useful here:

The student will get the same message whether he or she types “book” or points at a picture of a book displayed at location 1215. (The -or- command can be used to make synonomous any judging commands. The system variable “anscnt” will be the same for all judging commands linked by -or-.)

There is a random-access audio device which stores twenty minutes of speech, music, or other sounds. Segments as short as one-third second can be accessed in a fraction of a second, no matter where the segment is located on the twenty-minute magnetic disk. As with microfiche, students can change the disks themselves. There is a -play- command to choose a section of the disk to play music or talk to the student.

Other devices can be connected to the external output connector at the back of the PLATO terminal and controlled with the -ext- command. The -ext- command can send up to sixty 16-bit quantities per second to a device. Among the interesting devices using this capability is a “music box” that plays four-part harmony.

A crucial aspect of TUTOR on the PLATO system is that student response data can be collected easily to aid authors in improving lessons. Detailed information can be collected: unanticipated “wrong” responses (which may have been correct but inadequately judged), requests for help, words not found in a -vocabs-, etc. Summary information can also be collected: amount of time spent in an area of a lesson, number of errors made, number of help requests, etc. These detailed and summary data provide an objective basis for revising lessons.

A -dataon- command in a lesson turns on the automatic data collection machinery. Students registered in courses with associated response data files will have their responses logged in their data files. When registering students in a course, specific data collection options can be chosen. For example, one might collect only responses judged “no” (unanticipated incorrect responses). Anticipated correct responses (judged “ok”) and anticipated incorrect responses (judged “wrong”) would not be logged. This is often done because the anticipated responses are precisely those for which the lesson is already replying in a detailed, appropriate manner to the student. Here we see the difference between judge “no” (unanticipated) and judge “wrong” (anticipated). In this connection, -wrong-, -wrongv-, and -wrongu- make a “wrong” judgment, whereas the -no- command makes a “no” judgment.

The -area- command is used to divide a lesson into sections, each of which will produce an area summary in the data file. Each time the student encounters another -area- command, a summary of the previous area is placed in the data file. The area summary includes student name, area name, amount of time spent in the area, number of -arrow-s, number of ok/wrong/no responses, number of helps requested and found, etc. This summary data makes possible a statistical treatment of lesson data which can pinpoint weak areas.

The -output- and -outputl- commands permit you to write your own information and messages into the datafile. This supplements the automatic data logging invoked with -dataon- and -area-.

While PLATO provides a standard mechanism for looking through data files (including sorting the data), you can also read back this information and process it yourself. For example, the -readd- command will read area summaries or -outputl- information from a datafile previously specified by a -readset- command.

Usually in a lesson on a language such as Russian, which uses a special alphabet, the student will answer some questions in English and some duestions in the foreign alphabet. The responses in the foreign alphabet require a “force font”, or a “force font,left” for leftward-going languages such as Arabic, Hebrew, and Persian. Sometimes a “force micro” option will also be required in order to re-order the keyboard. Since there may he several things different about the two kinds of -arrow-s, it is convenient to have an alternate -arrow- command, which is named -arrowa-.

The -arrowa- command can cue the student differently, because you can alter the arrowhead displayed by -arrowa- by using the -arheada- command. The -arheada- command is similar to the -okword- and -noword- commands (the tag is what will be shown). Just as an -iarrowunit is associated with the -arrow- command, so the -iarrowa- command can be used to specify a unit associated with the -arrowa- command. Here is a typical setup:

Unit “ask2” has an -arrowa- command, which is associated with unit “persian”, the unit named in the earlier -iarrowa- statement. Unit “persian” clears out any existing -force- options and sets up the appropri- ate typing conditions for the student. Unit “persian” also redefines the words to be shown for correct and incorrect responses. The -answer- command in unit “ask2” has the Persian for triangle. The student will see a “←” instead of a “⪢” as a cue to give a response, thanks to the -arheada- command. On the other hand, the standard -arrow- command in unit “ask1” has associated with it the -iarrow- unit “english”, which clears the -force- options and sets the “ok” and “no” words to English words.

While this machinery is particularly valuable in language lessons, it is also useful whenever your -arrow-s fall into two rather different categories. An example might be a physics lesson in which some -arrow-s require sentence responses and other -arrow-s require algebraic or numerical responses.

Some additional TUTOR commands which are particularly help- ful in foreign language lessons include -change-, -getword-, -getloc-, -getmark-, and -compare-. As an example of the -change- command, the statement “change symbol comma to word” (which must be placed in the initial entry unit) will change the normal meaning of a comma as an ignorable punctuation mark, so that the comma will be treated as a separate word. This is useful when teaching punctuation, where you want to check specifically for commas. The -getword- command is similar to -storen- and is used to pull apart the student's response into separate words. The -getloc- command will tell you where a particular student word is on the screen, so that you could draw a box around that word. The -getmark- command gives you information on how TUTOR marked up the student's response, including whether a word was incorrect, mis- spelled, or out of word order. The -compare- command permits you to check a student's word against a stored list of words (in a common, for example), including spelling aspects.

Routers and -jumpout-