Searching for information could be difficult or problematic in situations where searchers possess inadequate knowledge and/or vague information needs, often leading to unsuccessful outcomes. Existing studies on search outcomes (successes and failures) have lacked a detailed analysis at query (expression of information need) level from a searcher's perspective and the connection between queries and their corresponding search tasks. In the work reported here, we adopt a mixed‐method approach to both explore how and why searchers succeeded or failed to fulfill their information need with each query and to link these query level outcomes to searchers' overall task goal realization. Twenty‐six participants finished two search tasks in three days in naturalistic settings and reported their experiences in online diaries. The log data containing their actions in nearly 200 query segments, their diary responses and post‐task semi‐structured interviews inspire both in‐depth discussion on search experiences and interesting comparison between successful and unsuccessful searchers. While quantitative analysis depicts the overall relationships between behavioral variables and search outcomes at both query and task levels, qualitative analysis reveals why those relationships took place. In general, searchers who viewed more pages and spent more time in each query segment were more likely to succeed. We also report reasons behind these phenomena.