In a systematic observation study, two different people use the coding system to analyze the same videotape. the level of agreement between the two observers is then determined. this activity addresses which methodological issue in systematic observation?
a) reactivity
b) reliability
c) sampling
d) validity

Option B

Explanation:

Reactivity, also referred as the spectator impact, happens when the demonstration of doing the exploration changes the conduct of members, along these lines making the discoveries of the research subject to mistake.  Reliability is to inquire about unwavering quality is how much research technique produces steady and predictable outcomes. A particular measure is viewed as solid if its application on a similar object of estimation number of times creates similar results.  Validity means that how stable your exploration is. All the more explicitly, validity applies to both the structure and the strategies for the undergoing research. Valid cases are strong claims. In research terms an example is a sampling of individuals, articles, or things that are taken from a bigger populace for estimation.