On several occasions I have used the following "drama" activity to explain how when using the web programming language HTML, text and pictures are not one piece of work (as with wordprocessing) - the text has a "gap" that tells the browser to find a particular picture and then show it. The act worked very well with four Year 8 classes at St Leonards-Mayfield School, East Sussex, who were doing websites and kept complaining that "the computer's lost my pictures" - it hadn't, the pictures just weren't where the computer was looking for them. (And yes, I had spent the previous three lessons reminding pupils that all their work should go into the file we'd made specially for this project.) Child A (the browser): holds up a piece of A4 showing scribbles for text and two squares with a Post-it Note in each to represent the pictures.
Child B (picture 1): holds up a picture connected by ribbon to the Post-it Note showing the same picture. Child C (picture 2): holds up a picture connected by ribbon to the other Post-it Note.
Child D is another file on the computer. The browser (Child A) is looking for the two pictures (Child B and Child C) and can show them because they are where it expects them to be.
If picture 1 is moved (give Child B's picture to Child D), the computer still looks where it expects the picture to be (the ribbon is still held by B) - but there's nothing there for it to show (remove corresponding Post-it Note from Child A).
If the picture is put back where it should be (give Child D's picture back to Child B) then the browser can see it again (replace Post-it Note).
This also works well, with a few adaptations, to explain the mysteries of saving. ("Miss, the computer's lost my work again...") Teresa Wilson, upper primarylower secondary education student (ICT), University of Brighton