In numerous species, egg chemoattractants play a critical role in guiding sperm towards unfertilized eggs (sperm chemotaxis). Until now, the known functions of sperm chemotaxis include increasing the effective target size of eggs, thereby promoting sperm-egg encounters, and facilitating species recognition. Here, we report that in the broadcast spawning mussel, Mytilus galloprovincialis, egg ch...

This study investigates differences in the partial scoring performance of examinees in elimination testing and conventional dichotomous scoring of multiple-choice tests implemented on a computer-based system. Elimination testing that uses the same set of multiple-choice items rewards examinees with partial knowledge over those who are simply guessing. This study provides a computer-based test a...

Dichotomous choice (or Referendum) contingent valuation surveys have become the predominate choice for valuing goods and services otherwise not valued in a standard market (nonmarket goods and services). A number of researchers have recently recommended that dichotomous choice contingent valuation studies include a follow-up question to all no responses to determine whether the no response is a...

In this note we conduct construct validity tests for dichotomous choice (DC) and polychotomous choice (PC) contingent valuation questions. Contrary to previous results, we find that DC and PC estimates of willingness to pay are theoretically valid, convergent valid, and similar in terms of statistical precision. Similar to previous results, PC respondents are less sensitive to information than ...