Planning and Carrying Out INVESTIGATIONS
"Planning and designing investigations require the ability to design experimental or observational inquiries that are appropriate to answering the question being asked or testing a hypothesis that has been formed."
Introduction to Planning and Carrying Out Investigations
Scientists and engineers investigate and observe the world with essentially two goals: (1) to systematically describe the world and (2) to develop and test theories and explanations of how the world works. In the first, careful observation and description often lead to identification of features that need to be explained or questions that need to be explored.
The second goal requires investigations to test explanatory models of the world and their predictions and whether the inferences suggested by these models are supported by data. Planning and designing such investigations require the ability to design experimental or observational inquiries that are appropriate to answering the question being asked or testing a hypothesis that has been formed. This process begins by identifying the relevant variables and considering how they might be observed, measured, and controlled (constrained by the experimental design to take particular values).
Planning for controls is an important part of the design of an investigation. In laboratory experiments, it is critical to decide which variables are to be treated as results or outputs and thus left to vary at will and which are to be treated as input conditions and hence controlled. In many cases, particularly in the case of field observations, such planning involves deciding what can be controlled and how to collect different samples of data under different conditions, even though not all conditions are under the direct control of the investigator.
Decisions must also be made about what measurements should be taken, the level of accuracy required, and the kinds of instrumentation best suited to making such measurements. As in other forms of inquiry, the key issue is one of precision—the goal is to measure the variable as accurately as possible and reduce sources of error. The investigator must therefore decide what constitutes a sufficient level of precision and what techniques can be used to reduce both random and systematic error.
Key Features
Development of comprehensive explanations and models through multiple investigations.
Investigation can be developed or modified based on students’ questions and interests.
Students determine the why and how investigations are carried out.
Authentic investigations in which students are working together to figure out what they need information about, planning how to get that information, and carrying out that plan.
What it is NOT
Cookbook labs in which students follow a set of procedures without considering how it is helping them figure something out.
“How to labs” that are aimed at teaching students procedural skills
Labs that require drawing or writing descriptions of items provided to them without a clear purpose.
“Cool activities” that have no clear purpose or linked to knowledge building.
K-12 Progressions for Planning and Carrying Out Investigations
SEP_PCOI.pdfInstructional Strategies for Planning and Carrying Out Investigations
Source: Instructional Leadership for Science Practices
Put students in small groups to complete investigations. Assign each student a job to do during the investigation. Model the job responsibilities before beginning the investigation so students understand what is expected of them while performing the investigation.
Assign groups to specific spaces in the classroom to conduct their investigations. This helps ensure each group has sufficient space to conduct their investigation and that the groups will not disturb each other.
Give students sticky notes to use to label materials in an investigation. This can help younger students or students who struggle with writing to show the outcome of an investigation without the demands of recording in a data table.
Have students vote on their prediction for the outcome of an experiment. Record predictions on the board. Ask students to revisit their predictions after they have gathered data.
Provide a scientific question and have groups of students design an investigation to answer the question. Provide students with a graphic organizer to record the variables (independent, dependent, constants), procedure, materials, and data table.
Show students several procedures for investigations that have varying numbers of trials, materials, or types of data tables. Ask students to critique the procedures based on the scientific question being explored.
Show students several procedures for investigations in which one only changes 1 variable while the others alter multiple variables at the same time. Ask students to critique the procedures to discuss the idea of a fair test and only changing one variable at a time.
Provide a choice of 3-4 scientific questions to explore about a specific topic. Have small groups of students select their question and design and carry out an investigation to answer that question.
Provide a general experimental procedure but allow student choice in terms of variables to be manipulated (e.g. materials to test, length of time).
Learn more about Planning and Carrying Out Investigations
Bozeman Science Video - Practice 3 - Planning and Carrying Out Investigations
Wonder of Science Organizer: Plan and Carry Out Investigations - Google Draw or PDF
STEM Teaching Tools - Practice Brief 19: Why should students learn to plan and carry out investigations in science and engineering?
Science Practices Continuum - Tool for guiding and evaluating science-practice based instruction