ALT tutorials • are learning-oriented • allow the newcomer to get started • are lessons Analogy: teaching someone how to cook How-to guides • are goal-oriented • show how to solve a specific problem • are a series of steps Analogy: a recipe in a cookery book Explanation: • is understanding-oriented • explains • provides background and context Analogy: an article on culinary history Reference: • is information-oriented • describes the machinery • is accurate and complete Analogy: a reference encyclopaedia article