In a field experiment to observe altruistic behavior, an observer records the number of people who stopped to hold the door for a student on crutches. She reports that seven people volunteered to assist the young man, when in fact there were only five. She has made an error called.

Inaccurate observation

Explanation:

Altruistic behavior is the attitude and act of people that show selfless care and good will a person has for other people in terms of supporting them,proving care or help.

According to the question,observer has generated the error of inaccurate observation as she did not precisely noted and noticed the people who actually assisted the man.Thus, she gave incorrect report of seven helping people rather than five people.

answer; i do believe that its(gestation,suction-aspiration or vacuum aspiration;

question - in 1827, john walker, a druggist in a small english town, tipped a splint with sulphur, chlorate of potash, and sulphid of antimony, and rubbed it on sandpaper, and it burst into flame. the druggist had discovered the first friction-chemical match, the kind we use to-day. it is called friction-chemical because it is made by mixing certain chemicals together and rubbing them. although walker's match did not require the bottle of acid, nevertheless it was not a good one. it could be lighted only by hard rubbing, and it sputtered and threw fire in all directions. in a few years, however, phosphorus was substituted on the tip for antimony, and the change worked wonders. the match could now be lighted with very little rubbing, and it was no longer necessary to have sandpaper upon which to rub it. it would ignite when rubbed on any dry surface, and there was no longer any sputtering. this was the phosphorus match, the match with which we are so familiar. according the paragraph what was the benefit of the new phosphorus match? it burst into flame when rubbed on sandpaper. it was made by mixing chemicals. it could be ignited on any dry surface. it threw fire in all directions.

answer - matches required natural chemicals