Invention activities are Productive Failure activities in which students attempt (and often fail) to invent methods that capture deep properties of a construct before being taught expert solutions. The current study evaluates the effect of scaffolding on the invention processes and outcomes, given that students are not expected to succeed in their inquiry and that all students receive subsequent instruction. While socio-cognitive theories of learning advocate for scaffolding in inquiry activities, reducing students' agency, and possibly their failure rate, may be counter-productive in this context. Two Invention activities related to data analysis concepts were given to 87 undergraduate students in a first-year physics lab course using an interactive learning environment. Guided Invention students outperformed Unguided Invention students on measures of conceptual understanding of the structures of the constructs in an assessment two months after the learning period. There was no effect, however, on measures of procedural knowledge or conceptual understanding of the overall goals of the constructs. In addition, Guided Invention students were more likely to invent multiple methods during the Invention process. These results suggest that the domain-general scaffolding in Invention activities, when followed by instruction, can help students encode deep features of the domain and build on their failures during Productive Failure. These results further suggest not all failures are equally productive, and that some forms of support help students learn form their failed attempts.