The relatively free word order that German exhibits is not entirely com- pensated for by rich morphology. Hence, local and even global structural ambiguities of the following form can quite easily arise.
(4.1) dass that die thef emsg:nom/acc Professorin professors die thef empl:acc/nom Studentinnen students gesehen seen hat/haben. has/have.
‘that the professor has seen the students’/‘that the professor was seen by the students.’
Since the element following the complementiser “dass” can either be the subject or the (scrambled) direct object of the clause, and the second ar- gument does not provide disambiguating information either, the parser will have to wait until the finite verb is processed to assign the structure an inter- pretation, i.e. assigning the thematic roles of experiencer and theme to the overt arguments. Note that the lexical verb, realised as a participle, does not help to disambituate either, since it is, out of context, equally plausible that the professor saw the students, as vice versa.
Early studies devoted to this phenomenon were Bayer & Marlsen-Wilson (1992), and Pechmann et al. (1994). Since the former in a way can be understood as a predecessor of the experiments to be reported in chapter 5, it will be considered in more detail in the next section.
The question Pechmann et al. (1994) were asking was what the preferred word order in the German Mittelfeld is. Since the Mittelfeld is the region where the scrambling operation can apply, the number of possible orders of
the three arguments of a ditransitive verb like “geben” (‘give’) is 3! = 6. To formulate a preference ordering on these orders, the authors conducted a se- ries of experiments applying different methods, including rating, recognition, and generation tasks. The data spoke in favor of a preference ranking of the following form:
(4.2) SDA > SAD > DSA > ASD > DAS > ADS
where S stands for the subject definite DP, D for the indirect and A for the direct object of DP form. The scale reflects decrease in acceptability from left to right, as well as an increase of processing difficulty in the same direc- tion, and basically accorded to the precedence rules formulated by Uszkoreit (1986).
For the question pursued here, the important point is that the order SDA, together with SAD, performed best in the experiments, which indicates that, in the German Mittelfeld, there is a preference for the subject to precede all other arguments.
This is in accordance with a lot of other findings produced since then, which mainly came from reading time studies and all studied the filler-gap ambiguity induced by topicalised or scrambled direct objects in transitive constructions. That is, the initial DP which is either subject or object pos- tulates a gap, but the structural position of the gap can not be determined until the whole structure is disambiguated.
Thus, Meng (1996) found the subject-first, or subject-before-object pref- erence, as it is sometimes called, to hold also for wh-structures like () in a self-paced reading study:
(4.3) Welche Which Lehrerin teacherf em:sg:nom/acc der of-the Stadtschule city-school hat/haben hassg/havepl die the Eltern parents angerufen? called?
’Which teacher of the city school called the parents/was called by the parents?’
The sentences with the plural auxiliary “haben” showed a garden-path effect, which can be explained in terms of the preference to assign the first ambiguous element the grammatical role of subject.
Similar data were obtained by Schlesewsky et al. (2000) for a less complex wh-phrase (‘which women’ instead of ‘which teacher of the city school’), and for wh-phrases moved out of an embedded clause.
The subject-first preference was also found to influence the processing of embedded clauses in a study Bader & Meng (1999), and even in ungram- matical sentences in a further study by the same authors (Meng & Bader, 2000).
Further studies using different methods added evidence to the subject- initial preference effect: ERP-studies by Mecklinger et al. (1995); and a series of experiments using the visual world paradigm conducted by Crocker (2002)..
The subject-first preference was also reported for Dutch by Frazier (1987) and Kaan (1996 and 1998), as well as for a non-Germanic language, namely Finnish, by Kaiser (2001).
Given this overwhelming evidence for the preference of the parser to assign the first argument encountered when parsing a sentence the grammatical role of subject, one may wonder why languages like German provide the option of inverting the order of subject and object in the first place. A possible reply to this is that all the studies reported so far did not embed the critical sentences into contexts, or if they did, these were question contexts. Hence, the conditions that the marked Information Structure of an OS sentence imposes on its context of appearance are not satisfied by that context.
Since it was argued in the preceding chapters that Information Structure serves the function to guide the parser in relating the sentence it is processing to the context, and that this context has to provide the right kind of structure to license word order variation, the question comes up how the parser deals with inverted object-subject order when these contextual requirements are fulfilled.