Pearson sought to explore whether the use of Bug Club, an online and in-print reading scheme targeted at ages 4-11, is related to pupils' literacy learning, attitudes to reading and school, and reading activity. This Research Report presents findings from one research study: a multi-approach evaluation we conducted in collaboration with University College London Institute of Education (UCL-IOE) during 2015 and 2016. The approach included a process evaluation to gather in-depth data on implementation and experiences of Bug Club, and a randomised controlled trial to measure the impact of Bug Club on learners. The findings appear alongside details of the research study, including a description of the sample studied, method of analysis, results, limitations and generalizability, and notes on possible future research. The report also summarizes the context surrounding the findings, including the research that informed the design and development of the product, the history of the product in the market, how educators use the product, and its intended outcomes. The findings are inseparable from their surrounding context and the design of the study that produced them. To learn more about these elements, follow the links to our Technical Reports in the Research studies section. In the context of the UCL-IOE study, conducted at 30 schools for primary school teachers and students using Bug Club to support English (Key Stage 1 and Key Stage 2), Pearson found that: (1) After 5.5 months, pupils using Bug Club made significantly greater progress in their reading than children in schools not using Bug Club as measured by the InCAS standardised reading assessment; (2) After 12 months, pupils using Bug Club continued to make highly statistically significant gains in their reading when compared to pupils not using Bug Club as measured by the InCAS standardised reading assessment; (3) After 18 months, pupils using Bug Club made significantly greater progress in their picture vocabulary than children in schools not using Bug Club; (4) After five terms, pupils in the Bug Club programme were 11 months ahead on their expected age equivalent reading score, relative to their chronological age as measured by the InCAS standardised reading assessment; and (5) After 5.5 and 12 months, Bug Club made a statistically significant impact on the reading gains of children in receipt of pupil premium as measured by the InCAS standardised reading assessment.