Methodological weaknesses and limitations

Methodological weaknesses can be reduced with better instruments, improved control of variables, or improved technique without changing the scientific question.

Examples of some weaknesses could be:

• ruler parallax

• relying on human reaction time

• unstable clamp

• low resolution thermometer

• low frame rate for filming

The effects of these weaknesses might include:

• reducing the precision of the data

• reducing the repeatability of the data

• increased random/systematic errors

Methodological weakness: Manual stopwatch timing introduced ±0.2 s reaction uncertainty.

Scientific effect: At short oscillation periods this represented up to 8% uncertainty, increasing vertical scatter and broadening gradient uncertainty.

Improvement: Use high-frame-rate video capture with frame-by-frame motion analysis to determine timing to ±0.01 s.

Expected impact: This would reduce percentage uncertainty below 1%, tighten clustering of points, and produce a more constrained best-fit gradient for comparison with theoretical SHM predictions

Limitations are fundamental constraints of the investigation that cannot be fixed without changing the research question or experimental scope.

Examples of some limitations could be:

• neglecting air resistance

• assuming ideal elasticity

• assuming constant temperature

• assuming point masses

• assuming no rotational energy losses

• laboratory conditions not representing real-world systems

• independent variable range too narrow to test breakdown of theory

The effects of these limitations might include:

• lower external validity

• lower theoretical validity

• less explanatory power/ability to generalise