About the Continuous IOS


What is it?
The Inclusion of Other in the Self scale was originally designed by Dr. Art Aron and colleagues (Aron, Aron, & Smollan, 1992) as a measure of self-other inclusion and relationship closeness (click here to see the original measure). The Continuous IOS makes use of the basic design of the original IOS, but allows for (a) the measure to be embedded within a web-based questionnaire, (b) the output values to be continuously scaled, and (c) modifications in the appearance and behavior of the measure.

The Continuous IOS runs on an applet written in Java. Therefore, Java needs to be installed on your computer for the applet to work. Click here to see if your computer is configured to run the applet (i.e., if Java is correctly installed). If Java is not installed, you'll be able to download it.

Demostration of the applet.
Click here to see a demo of how the applet works, including the values that are outputted.

How it's used.
Click here to see examples of the applet embedded in on-line questionnaires.
Essentially, it is used to replace the standard "fixed points" IOS that is typically used in a paper and pencil surveys. In addition, see some of the modifications that can be made to its appearance and behavior.

Click here to see the documentation for using and editing the applet. These detailed instructions include how to change the color and size of the background of the applet and the circles, as well as how to edit the circle labels. In addition, the default position of the circles can be changes, as well as allowing the first circle to go "backwards" (i.e., "negative distance")

Click here for information about downloading the Continuous IOS applet.

Thanks to Will Moss (Haverford College, '05) for creating the script for the applet and writing the documentation. If you have any questions about the Continuous IOS please contact Benjamin Le (ble@haverford.edu).


Agnew, C. R., Loving, T. J., Le, B., & Goodfriend, W. (2004). Thinking close: Measuring relational closeness as perceived self-other inclusion. In D. Mashek & A. Aron (eds.), Handbook of Closeness and Intimacy (pp. 103-115). Mawah, NJ: Lawrence Erlbaum Associates.

Aron, A., Aron E. N., & Smollan, D. (1992). Inclusion of other in the self scale and the structure of interpersonal closeness. Journal of Personality and Social Psychology, 63, 596-612.

Aron, A., Aron, E. N., Tudor, M., & Nelson, G. (1991). Close relationships as including other in the self. Journal of Personality and Social Psychology, 60, 241-253.

Le, B., Moss, W. B., & Mashek, D. (2007). Assessing relationship closeness on-line: Moving from an interval-scaled to continuous measure of including others in the self. Social Science Computer Review, 25, 405-409. <<<< Click for PDF of the paper