Phrase structure analyses of partial verb phrase (hence: PVP) fronting in German recognize PVPs as potential constituents---i.e, they are constituents not only in the Vorfeld, which they can and must be, but existing analyses inevitably have the consequence that PVPs are potential constituents in the Mittelfeld as well. Given the range of frontable PVPs this has the undesirable consequence that a great deal of otherwise unmotivated phrase structure is postulated in the Mittelfeld, which, moreover, must be assumed to provide alternative constituent structures---the structures overlap in ways incompatible with simple tree structures. Haider has noted this problem, which results in the postulation of spurious ambiguity---structural ambiguity which appears to have neither semantic correlate nor syntactic motivation. This is a problem which Pollard's "On Head Non-Movement" ends with, and the contribution here is a simple suggestion on how to avoid these unwanted ambiguities. The suggestion ...

We propose a bottom-up variant of Earley deduction. Bottom-up deduction is preferable to top-down deduction because it aJlows incremen- tal processing (even for head-driven grammars), it is data-driven, no subsumption check is needed, and preference values attached to lexical items can be used to guide best-first search. We discuss the scanning step for bottom-up Earley deduction and indexing schemes that help avoid useless deduc- tion steps.