The main methodological point I intended to make in my JK presentation is a general point that underlies the remarks at the end of section 4 of my Lingua paper, repeated here.

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　　　It is thus possible to find empirical materials that are consistent with (some of) the predictions in (121). This is not surprising. Popper (1959) warns that "it is always deceptively easy to find verifications of a theory." What is predicted by (120) is not (135a) but (135b).

(135)　a.　There are empirical materials that are consistent with (121).
　　b.　There are no empirical materials that are not consistent with (121).

The intent of Popper's remark that "we have to adopt a highly critical attitude towards our theories if we do not wish to argue in circles: the attitude of trying to refute them" seems to be precisely this—in the context of the present discussion.⁸²

FN 82　　The relevant passage is given in (i).
(i)　　[O]bservations, and even more so observation statements and statements of experimental results, are always interpretations of the facts observed; that they are interpretations in the light of theories. This is one of the main reasons why it is always deceptively easy to find verifications of a theory, and why we have to adopt a highly critical attitude towards our theories if we do not wish to argue in circles: the attitude of trying to refute them. Popper (1959: 107, footnote *3)
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For your easy reference, I repeat (120) and (121).

(120)　Standard Assumption/Hypothesis:
　　Otagai is a local anaphor.
(121)　Predictions made by (120):
　　a.　Otagai requires a linguistic antecedent.
　　b.　Otagai must be c-commanded by its antecedent.
　　c.　Otagai must be c-commanded by its antecedent in its local domain.
　　d.　Split antecedence is not possible for otagai.

　　What has happened, and is still happening, so it seems, with respect to otagai is a fairly transparent case where a given research is concerned with, and seems 'content' with, the demonstration that there are empirical materials that are consistent with the proposal in question. And if those empirical materials are, or appear to be, consistent with what is being claimed/adopted/assumed, they are taken to be evidence for it.
　　My JK presentation was meant to illustrate, by making reference to particular analyses of passives in Japanese, how one might proceed with the attitude of trying to refute the hypothesis one puts forth. To make my point, I emphasized the importance of 'negative propositions' and 'negative predictions'. In so doing, however, I made it sound as if it were not important to obtain confirmation for 'positive propositions' and 'positive predictions. This was pointed out to me by Bill McClure after my presentation. He pointed out that my presentation might have given, or perhaps gave, the audience who is not familiar with my work the impression that I do not care about obtaining confirmation for 'positive propositions' and 'positive predictions'. I do, and that is fairly obvious in my Lingua paper and elsewhere. But I am not content with that; in order to make our hypothesis falsifiable, I want to be able to deduce 'negative propositions' and 'negative predictions' from it. Furthermore, I want to be able to state exactly how one can conduct experiments to test such predictions.