Science & Engineering Practices:
4. Analyzing and Interpreting Data
Once collected, data must be presented in a form that can reveal any patterns and relationships and that allows results to be communicated to others. Because raw data as such have little meaning, a major practice of scientists is to organize and interpret data through tabulating, graphing, or statistical analysis. Such analysis can bring out the meaning of data--and their relevance--so that they may be used as evidence.Engineers, too, make decisions based on evidence that a given design will work; they rarely rely on trial and error. Engineers often analyze a design by creating a model or prototype and collecting extensive data on how it performs,including under extreme conditions. Analysis of this kind of data not only informs design decisions and enables the prediction or assessment of performance but also helps define or clarify problems, determine economic feasibility, evaluate alternatives,and investigate failures.(NRC Framework, 2012, p. 61-62)
As students mature,they are expected to expand their capabilities to use a range of tools for tabulation, graphical representation, visualization, and statistical analysis. Students are also expected to improve their abilities to interpret data by identifying significant features and patterns, use mathematics to represent relationships between variables, and take into account sources of error. When possible and feasible, students should use digital tools to analyze and interpret data. Whether analyzing data for the purpose of science or engineering, it is important students present data as evidence to support their conclusions. Analyzing data in grades 3–5 builds on previous experiences and progresses to introducing quantitative approaches to collecting data and conducting multiple trials of qualitative observations.When possible and feasible, digital tools should be used. - Represent data in tables and/or various graphical displays (bar graphs, pictographs and/or pie charts) to reveal patterns that indicate relationships. - Analyze and interpret data to make sense of phenomena, using logical reasoning, mathematics, and/or computation. - Compare and contrast data collected by different groups in order to discuss similarities and differences in their findings. - Analyze data to refine a problem statement or the design of a proposed object, tool,or process. - Use data to evaluate and refine design solutions. |
Scientists and engineers employ analysis and interpretation to see if their data can answer their questions.
Data analysis includes organizing and presenting the data to find patterns. We then interpret those patterns to understand what they mean. The first stage of analysis is to ensure that the data are reliable . Did we collect the data correctly? Do all the observations reflect the process we're investigating? Errors can be random (e.g. measuring errors due to imprecise tools or small variations in the object itself), or systematic (e.g. a mistake in calibrating a scale, leaving out an important variable in a computer simulation program, or biased data). To minimize errors, we might collect many observations. The next stage of analysis is to average those observations or perform any other statistical analysis. The final stage of analysis is presenting the data in a usable form, often as graphs and data tables. Scientists begin to get answers to their questions when they interpret the data. They recognize trends and patterns in the data and use these to infer cause and effect relationships. At times, scientists can't get a definite answer from the data (e.g. not having enough data or ambiguous data sets); students need to experience these situations so they understand that science is not about finding the “right answer.” |