PHY.1:4.1 - Choose the physical result and the proposed change

Name the original arrangement and the comparison arrangement. Say what each does and what the comparison is intended to reveal. Distinguish a proposed experiment from an observed one.

Specify the result at the detail needed for its use: total extension under a load, the location of a maximum, a response after a stated duration, or a distribution of repeated outcomes. Include the location, interval and preparation when they affect that result. A request for average deformation differs from a request for deformation at every point.

Identify what may change between the arrangements and what is fixed by the proposed work. The available fluid, gravitational acceleration, material, instrument range or support can constrain the construction. A control may be a time history rather than one setting. Preserve any known dependence between settings: changing temperature can alter both viscosity and density.

If the existing physical account already yields a sufficient answer, use it. Constructing another experiment is worthwhile when it supplies a contribution the work still needs. C.11.DUA helps choose between acting on a sufficient answer and obtaining more information.