Acme Foods wants to make its chips saltier, but it doesn't want to spend more than it has to on salt. A sample of consumers are asked to compare its current chip (saltiness = 100) with saltier versions and to say whether the new version is saltier. On average, sample consumers reliably say the new chip is saltier when its saltiness value is 108, but not when its saltiness value is below 108. Assuming Acme Foods' sample consumers are representative of people in general, which of the following best represents the just noticeable difference for saltiness?
8%

Reliability and validity reliability and validity are two important considerations that must be made with any type of data collection. reliability refers to the ability to consistently produce a given result. in the context of psychological research, this would mean that any instruments or tools used to collect data do so in consistent, reproducible ways. unfortunately, being consistent in measurement does not necessarily mean that you have measured something correctly. to illustrate this concept, consider a kitchen scale that would be used to measure the weight of cereal that you eat in the morning. if the scale is not properly calibrated, it may consistently under- or overestimate the amount of cereal that’s being measured. while the scale is highly reliable in producing consistent results (e.g., the same amount of cereal poured onto the scale produces the same reading each time), those results are incorrect. this is where validity comes into play. validity refers to the extent to which a given instrument or tool accurately measures what it’s supposed to measure. while any valid measure is by necessity reliable, the reverse is not necessarily true. researchers strive to use instruments that are both highly reliable and valid.