User: The greenhouse effect is a result of A. absorption and radiation of energy in the hydrosphere. B. consumption of fruits and vegetables that produce a biofuel. C. absorption and radiation of energy in the atmosphere.
A principal focus or focal point is a special focus: 1  For a lens, or a spherical or parabolic mirror, it is a point onto which collimated light parallel to the axis is focused. Since light can pass through a lens in either direction, a lens has two focal pointsâone on each side.
Focus Groups. A focus group is a moderated discussion that typically involves 5 to 10 participants. Through a focus group, you can learn about usersâ attitudes, beliefs, desires, and reactions to concepts. Focus groups are a traditional market research technique. Marketing departments are often more familiar with focus groups than with usability testing or contextual interviews. However, the techniques produce different kinds of information. In a typical focus group, participants talk.