Events require other events to establish necessary conditions for their occurrence. The Link Events form asks questions that help you identify which events in a narrative are prerequisites for other events. The elicitation procedure taps your understanding of the process in order to build a formal model.

Events must be defined and time ordered before beginning the task of specifying event linkages.

Components of the Linking Display

Controls

A popup menu titled Type of question allows you to use different elicitation questions.

Radio buttons under the label Begin questioning with: allow you to change the order in which questions are asked.

A Redo button restarts questions regarding the event shown just above the button.

A Done button terminates questions regarding the event shown just above the button, leaving the links established in prior questions.

The button labeled Start over from the beginning allows you to clear all linking information.

Elicitation Question

The elicitation question presents two events within a question frame. Yes and No buttons allow you to answer the question. A Next question button records your answer and displays the next question.

Chart

A thumbnail chart showing linkages among events is displayed at the middle of the screen. (Select Chart in the Operations menu to see the full-size chart with event names.)

Notes

A scrollbox titled Record of answers and comments indexes all questions that have been asked, and indicates whether the answer to each question generated a link or not. You can type comments in this box.

Information is appended in this box when you change linkages by editing the chart, or while testing a model.

The entire linking history is included in the saved data when you export a model.

Specifying Linkages

The basic procedure is as follows.

1. An event name is printed in the topmost box at the right of the screen, and another event name is printed in the box below it. The two event descriptions are embraced within a question asking you if the events relate. Answer the question by clicking either the Yes or No button below the boxes.

   The texts appearing in the boxes are full descriptions of events if you have entered such descriptions. Otherwise the boxes show the short names of the events.

   The Yes and No buttons disappear after you click one of them. This is a time when you can enter comments. The buttons reappear as usual when the next question is presented.

   Initially the next-question button says either No. Next question or Yes. Next question. Clicking this button instead of Yes or No records that a linkage is lacking, and you move directly on to the next question. Absence of linkage is common and often uninteresting, so you may be willing to bypass the Yes and No buttons and the opportunity to type comments.

   You may click the Done button at the point where you have specified all of the linkages of the event printed above the button. This saves you from having to click the No. Next question button repeatedly in answer to additional linkage questions for that event.

2. Your answer is recorded in the Record of answers and comments box at the bottom of the screen. You may click in the box to type remarks of your own, in particular about why events are linked.

   The record of answers is structured as follows. The short name of the focal event is printed on a separate line as a heading. The answer to each question about the focal event is printed on an indented line. Each indented line identifies the other event in the question by the other event's short name. The line then specifies whether or not the other event was linked as a prerequisite to the focal event. The kind of question and the direction of questioning are specified in parentheses.

3. Click on the Next question button. Once again, two event descriptions will be presented, embraced within a question. Continue answering the questions until the program announces that you have reached the end.

Forms of the Elicitation Question

The question that you are asked can be varied by selecting from the Type of question pop-up menu. The four options are:

• Prerequisite: Does ___ require ___ or a similar event?
• Implication: Does occurrence of ___ imply ___ or a similar event?
• Historical Causation: Is ___ or a similar event a cause of ___ in the circumstances that existed?
• Counterfactual: Suppose an event like ___ does not occur. Can ___ occur anyway?

The last two questions reverse the placement of the events in the boxes, as compared to the first two questions.

The questions are equivalent logically. Answering Yes to the first three questions, or No to the counterfactual question, indicates that the two events are linked. Answering No to the first three questions, or Yes to the counterfactual question, indicates that the two events are not linked.

Switch among these questions as desired when you are linking two events. One form of question may seem more lucid than the other forms.

Order of Questions

Under the title Begin questioning with: are two radio buttons at the left of the screen, End events and Initial events. These control the order in which questions are asked.

If you select End events the program develops questions about a focal event by starting with events that have the longest strings of prerequisites. This eliminates many questions if the focal event is linked to an event at the end of a prerequisite string. Answering that the focal event requires the event means that the focal event also requires all of the event's prerequisites, so questions about the prerequisites are skipped.

If you select Initial events the program develops questions about a focal event by starting with events without specified prerequisites. This avoids many questions if the new event is not dependent on any of the events in a long prerequisite string. Answering that the focal event does not require another event means that the focal event is not dependent on any of the other event's consequences, so questions about the consequent events are skipped.

In general, it is easier to answer questions involving end events, and the chances of answering wrong are less.

Changing Answers

If you give a wrong answer and you catch your error while the program still is asking questions about the same focal event, you may start over and re-answer the questions for that focal event.

Click the Redo button. The program forgets answers you gave regarding the focal event, and re-starts the series of questions regarding the focal event. Your answers about prior focal events are retained.

Otherwise an erroneous answer is best corrected by selecting Chart from the Operations menu. You can add or delete links graphically.

You can jettison all answers given in a linking elicitation, and start over, by clicking the button named Start over from the beginning.

Using the Thumbnail Chart

The thumbnail chart showing linkages among events indicates events by dots rather than by names. You can determine the name and description of a dot's event by pressing the Control key and clicking on the dot. The information about the event is presented in a dialog window, which can be removed by clicking Okay.

The chart is updated each time you complete elicitation questions for a focal event.

The chart also tracks your progress in answering elicitation questions about a focal event by using different colors for dots.

• Black dots are events whose relation to the focal event is yet to be determined.
• A green dot shows the structural position of the event currently being considered in regard to its linkage to the focal event.
• Yellow dots show events whose linkage to the focal event is known. The linkage information may be a direct result of your answer to a linkage question, or the information may have been deduced from the logical structure of events.

URL: www.indiana.edu/~socpsy/ESA/Linking.html