Purposive sampling means: a. selecting sample members to study because they possess attributes important to understanding a research topic. b. selecting sample participants who can generate spontaneous discussion on a research topic. c. selecting sample members so that groups can be compared. d. selecting sample members based on earlier interviews. e. selecting particular types of participants because they can minimize cross talk during the discussions of a research topic.

a. selecting sample members to study because they possess attributes important to understanding the research topic.

Explanation:

A purposive sampling is a sampling technique in which the researchers rely on their own decision or judgement in choosing the members of the population of the study. This is a non-probability sampling as no random selection is made.

This sampling method needs the researcher must be possessing prior knowledge about the purpose of the study so that the researcher can choose the desired and eligible members for the study.

the earth’s crust is broken into separate pieces called tectonic plates (fig. 7.14). recall that the crust is the solid, rocky, outer shell of the planet. it is composed of two distinctly different types of material: the less-dense continental crust and the more-dense oceanic crust. both types of crust rest atop solid, upper mantle material. the upper mantle, in turn, floats on a denser layer of lower mantle that is much like thick molten tar.

each tectonic plate is free-floating and can move independently. earthquakes and volcanoes are the direct result of the movement of tectonic plates at fault lines. the term fault is used to describe the boundary between tectonic plates. most of the earthquakes and volcanoes around the pacific ocean basin—a pattern known as the “ring of fire”—are due to the movement of tectonic plates in this region. other observable results of short-term plate movement include the gradual widening of the great rift lakes in eastern africa and the rising of the himalayan mountain range. the motion of plates can be described in four general patterns:

collision: when two continental plates are shoved together

subduction: when one plate plunges beneath another (fig. 7.15)

spreading: when two plates are pushed apart (fig. 7.15)

transform faulting: when two plates slide past each other (fig. 7.15)