Evidence-based practice

What is evidence?

The previous section drew a distinction between inquiry and research. Two other words that tend to be used interchangeably are “data” and “evidence”. According to Earl and Katz (2002):

Data are summaries that result from the collection of information through systematic measurement or observation or analysis, about some phenomenon of interest, using quantitative and/or qualitative methods.

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Many commentators have made the point that educational institutions are awash with data and that much of it is not used well (Earl and Katz, 2002; Stoll et al., 2003). Data is only of value when its collection and analysis is purposeful. That means that it is tied to identified needs and goals and it is used to make decisions (Mid-continent Research for Education and Learning, 2003).

The value and utility associated with data come from the care with which the information has been collected and collated and from transforming these symbols into knowledge by shaping the information, organizing it and thinking about what it might mean, in relation to other available knowledge. This is a human activity that requires not only capturing and organizing ideas but also turning the information into meaningful actions (Senge, 1999).

Earl and Katz, 2002, page 1005

Data becomes evidence when it is used as a means of asking deeper, more complex questions and focusing investigations. As Earl and Katz put it, interpretation is paramount:

Data and statistics may provide the tools for measuring important educational concepts, but the numbers are only as good as the thinking that goes into the interpretation.

… Interpretation requires time, thoughtfulness, reservation of judgments and open challenge of, as well as support for, ideas. Very often, it also requires more information along the way to clarify or extend the possibilities. Interpretation, then, is thinking – formulating possibilities, developing convincing arguments, locating logical flaws, and establishing a feasible and defensible notion of what the data represent.

page 1015

Evidence, then, is the data we select – the relevant information that we notice from the external research work and from our own practice – and the interpretations we make from that data. The process of interpretation is one of sense-making: asking questions about the data to create new and useful knowledge. Spillane, Reiser, and Reimer (2002) identify four steps in the sense-making process: noticing, framing, interpreting, and constructing meaning. This takes time, effort, and the use of prior knowledge.

All acts of understanding require accessing prior knowledge and applying it to guide the noticing, framing, and connecting of new ideas and events to what is already encoded in memory (Mandler, 1984; Rumelhart, 1980).

Spillane et al., 2002, page 394

Making sense of the data that has been gathered, whether it is formal, statistical information or less formal, qualitative information, requires the inquirer to ask serious, complex questions. The inquiry questions listed below are adapted from some developed by Stoll et al. (2003, page 145). They provide a useful way of reflecting on inquiry findings so that the interpretations made from data are meaningful.

• What do you think these findings tell you? Why?
• Now step outside the obvious interpretations and challenge your existing thinking and experience. What might these findings mean?
• Who are the different audiences that might be interested in these findings? What questions will they want answered? What evidence will they accept that your interpretations are correct?
• What don’t these findings tell you? What’s missing? What else do you need to know? How can you find this out? Who can help you?
• What questions do these findings raise for you? How will you go about answering these questions?
• How can you use these findings to help you increase your learning?

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