Reading is a process of forming and evaluating hypotheses to account for the data in a text. Because of its complexity, the task of reading requires strategies for controlling the proliferation of hypotheses. Four of these strategies are (1) jumping to conclusions, (2) maintaining inertia (refusing to abandon a hypothesis in spite of contradictory evidence), (3) relying on background knowledge, and (4) working backwards from the goal (choosing hypotheses that are clearly and directly related to the goal despite insufficient evidence). These strategies are necessary and are used to good effect by successful readers, but they also sometimes lead to unexpected difficulties. Understanding the reading process from this perspective of hypothesis testing can help teachers diagnose underlying causes of poor reading comprehension. Examples from oral protocols of children and adults answering questions about a reading test passage illustrate both the effective use of the strategies and some of the problems arising from their use. (RL)