You've never had the most basic class in statistics and probability. I thought you claimed to have a PhD in geology. Those two facts don't jibe well.
Increasing the Ability of an Experiment to Measure an Effect
Increasing the Ability of an Experiment to Measure an Effect
Sandra Slutz, PhD, Staff Scientist, Science Buddies
Kenneth L. Hess, Founder and President, Science Buddies
All experimental observations are a combination of
signal, the true effect of a variable on an outcome, and
noise, the random error inherent in your experimental technique. When designing and analyzing experiments, the goal is to maximize the signal-to-noise ratio so that you can draw accurate conclusions.
Six common means of increasing the signal-to-noise ratio are:
- Making repeated measurements of one item,
- Increasing sample size,
- Randomizing samples,
- Randomizing experiments,
- Repeating experiments, and
- Including covariates.
How Sample Size Affects the Margin of Error - dummies
The relationship between margin of error and sample size is simple:
As the sample size increases, the margin of error decreases. This relationship is called an inverse because the two move in opposite directions. If you think about it, it makes sense that
the more information you have, the more accurate your results are going to be (in other words, the smaller your margin of error will get). (That assumes, of course, that the data were collected and handled properly.)
4. GENERAL SAMPLING CONSIDERATIONS
4.2.1 Sampling Accuracy
- Sampling accuracy is usually expressed as a relative index in percentage form (i.e. between 0 and 100%) and indicates the closeness of a sample-based parameter estimator to the true data population value.
- When expressed as a relative index, sampling accuracy is independent of the variability of the data population, i.e. data population parameters of high variability can still be estimated with good accuracy.
- When sample size increases and samples are representative, sampling accuracy also increases. Its rate of growth, very sharp in the region of small samples, becomes slower beyond a certain sample size.