Which of the six sources of control over asking experimental questions provides info about what is currently significant in the field?

What percentage of time was the response present if using a whole-interval time sample approach with a 30 min measurement session divided into six 5-min segments you observed the following: seg-1: duration = 4min and 38 sec seg-2: duration = 3min seg-3: duration = 5min seg-4: duration = 5min seg-5: duration = 4min and 45 sec seg-6: duration = 5min  

The unit of measurement for rate is [answer-1]/[answer-2] 

Which of the six sources of control over asking experimental questions provides info about what is currently significant in the field?

Time sampling should be used (when)

A measurement system must be designed to only record those features of the [answer-1] and the [answer-2] that are relevant to the study

During pregnancy, women should try to ________ daily to aid in a healthy pregnancy.

The unit of measurement for rate is [answer-1]/[answer-2] 

Which of these conditions indicates that a woman needs to pay particular attention to the quality of her diet during pregnancy?

A measurement system must be designed to only record those features of the [answer-1] and the [answer-2] that are relevant to the study