Summary.Both dispositional and attributional perspectives on perceptions of control assume that people have some idea of outcome determinants. This, however, may not always be so. This study tested the hypothesis that pupils do not always understand the determinants of their learning outcomes, and that such a sense of unknown control will be associated with poor achievement in school. The study was unusual in that it tapped both dispositional control perceptions, using the new MMPCC, and causal attributions for success and failure in a school examination. Subjects were 186 10‐year‐old Israeli pupils of heterogeneous SES. Results confirmed that unknown control emerged as a distinct dimension of perceived control in both dispositional and attributional measures, and was consistently associated with poor achievement in school. Attributions of test outcomes to unknown causes were strongly related to dispositional unknown control, and were not affected by success or failure. In contrast, dispositional and attributional internality were unrelated, and did not predict achievement. It is argued that internal beliefs reflect internalised social‐educational norms, and as a result have less impact on motivation than perceptions of unknown control. The implications of these findings for educational practice and motivational interventions are disc