The literature search will be supplemented by scanning the reference lists of included studies, searching authors' personal files, and contacting methodological experts in each field.
Following Gadrey [19] and Gallouj [22], we distinguish four types of operations in freight transport: material operations (the basic object of transport), treatment of (codified) information, relational or contact operations, and methodological operations (Table 1).
Our typology of freight transport operations identifies and describes different service trajectories which are based on material logistic operations, but can include to various degrees the treatment of information, contact operations, and methodological operations.
Authors were contacted for further methodological detail, but no additional information was provided.
3, Since the quantification of the intensity of contacts is characterized by methodological difficulties (the number of contacts does not always turn into quality), I used the scores, based on available information: 0 point no ties 1 point connection exists; however, financial information is not provided or the total annual turnover of affiliated companies is less than ten million RUB.
The trial co-ordinator will immediately contact the clinical and methodological chief investigators who have been delegated the responsibility of reporting any serious adverse events on behalf of the sponsor (Bangor University).
No attempt was made to contact authors, so that the methodological quality may rather relate to reporting quality and the way the study was conducted may be of better quality than reflected in the article.
Although the authors of one trial [ 49] were contacted for additional information about methodological aspects, this information could not be obtained.
A methodological discussion concerns the way social contact should be provided in operant conditioning studies.
Detractors worry about their inability to contact voters in cellphone-only households and other methodological shortcomings.
