Theory Maker is a free web app by Steve Powell for making any kind of causal diagram, i.e. a diagram which uses arrows to say what contributes to what. You make the diagrams just by typing the names of the elements (called variables) in a structured way into a (resizeable) window, and you get a live diagram as output which reflects what you type. In particular, it is optimised for making theories of change, logframes, etc. - special kinds of pragmatic causal theory which are particularly popular at the moment in the world of monitoring and evaluation (M&E). Theory Maker is most often used by M&E staff for quickly sketching out project theories and evaluation plans. But scientists, especially social scientists, and policy makers use it too.

Features: Human-readable syntax. Two different ways to “draw” lines between variables, so you can use whatever is most convenient. Recognises and makes auto links for standard decimal naming conventions beginning with a number. Boxes for putting variables in groups, for example to mark off different phases, places or participants. Format your variables and boxes with colours, fonts etc. Easy to change diagram direction (left-to-right, top-to-bottom, etc.) and diagram proportions (wider, taller etc.). Easy to add cross links even in mainly hierarchical theories, e.g. from one sub-Outcome to more than one Outcome You can create aliases/labels for your variables to save tiresome retyping Add notes, “calendar bars” and many other bells and whistles Lots of live templates and suggestions for your theory of change, ready for you to edit (don't worry, you aren't editing the originals). Each new diagram gets a unique permanent link which you can bookmark to return to later or send to a friend. Anyone can save changes to this link.