Original empirical study

You collect new data and analyze it. The most work and the most rewarding. Everything from a lab experiment to a survey to a coded set of interviews fits here.

Shape: abstract → introduction → methods → results → discussion → limitations → references.

Length: 10–20 pages. Common mistake: a sample too small to say anything. Decide how many you need before you start, and if you can't get it, say so honestly in limitations.