In the design of this investigation, I stated that eighty people would be sampled. However, I decided to sample one hundred people (fifty males and fifty females), as results collected from fewer individuals would give rise to greater anomalies. By taking a larger sample, readings can be taken from a broader cross section of the population so that a more accurate view of the correlation between foot length and hand span could be gained.
iv) Environment - Each human being has a slightly different environment that will affect the way in which they grow and develop. However, differences in environment should not affect the feet and hands separately and therefore individuals with varying environments, home life or backgrounds could still be compared without excessive anomalies.
v) Measurements - In this investigation the right foot length and right hand span of individuals was measured and compared. By measuring the right hand and foot only, differences between the right and left hand and the right and left foot could be taken into account. To do this effectively, the foot length and hand span was clearly defined so that measurements were taken consistently and compared accurately. All measurements were taken using a standard metre long tape measure. Each measurement was recorded to the greatest degree of accuracy possible (nearest millimetre).
Hand span: The hand span was measured from the tip of the thumb to the tip of the little finger when the hand and fingers are stretched out flat on a surface. This measurement excluded any length of fingernails extending past the ends of the fingers. By defining the hand span to be measured, discrepancies between measurements should have been reduced giving rise to more accurate and reliable results.
Foot length: The foot length was measured from the back of the heel to the end of the big toe when placed on a flat surface. This measurement excluded any nail extending over the end of the toe.