Concept tests in the screening and evaluation stage of the new-product process rely on written descriptions, sketches, or mock-ups rather than to solicit feedback from potential consumers.

The answer is "Actual products".

Explanation:

The key purpose of this research is to better analyze the concepts, which is done to establish customer buying expectations and perceptions of the item. The key point is to assess the consumers ' initial response to the product idea.

This concept testing is also known as a creation, it is an advantage, which can be conveyed to the user to test their reactions.  In conceptual testing, it is a quality check between the design definition and the actual production of the product.

answer: when the substance contain the two parts (polar and non-polar) like soap.

explanation:

soap is produced from the basic hydrolysis of ester "saponification", it is considered as a salt of hydrocarbons. the soap molecule contains the two parts: a polar group   (-coo-na+) and a non-polar group (r-hydrocarbon part). the polar group is called the head and the tail is the non-polar group. the polar group is hydrophilic in nature (water loving) and the non-polar group is hydrophobic in nature (water repelling).the polar/non-polar nature of a substance is useful that it can dissolve the non-polar substances by the polar part and also can dissolve the polar substances by the non-polar part. it commonly used in detergents and soaps.