In addition to the modes of substitution outlined in Table \ref{table:technology_categories}, other technologies have been identified as 'non-starters': these are technologies that were never mass commercialised. In many cases these technologies could have been adapted for the target markets considered but were either never used or failed to demonstrate the required features, or performance and cost improvements necessary to warrant further development beyond initial trials. Examples of non-starter technologies include wire recorders as an alternative to magnetic tape technology and chain printers as an alternative to dot matrix printers. In the case of wire recorders, this format failed to take-off after it was excluded from the standard-setting process in favour of magnetic tape technology, leading to “technological lock-out”, whilst early chain printers were quickly eclipsed by the superior performance of the dot matrix design. Non-starters are excluded in this study, as the analysis that follows is based on classifying individual technologies based on technologies that are known to have been successfully commercialised, and as such it is not believed their inclusion would influence the results presented here, although non-starters would need to be included for reducing uncertainty in the classification of emerging technologies \cite{Sood_2005}.
Based on Constant's hypothesis regarding scientific and technological anomalies and their influence on the mode of technological substitution, this paper looks to test whether bibliometric measures of scientific and technological development can provide an indication of the mode of adoption likely to occur. Consequently, this study theorises that in order to identify cases of technological substitution arising from presumptive anomaly a classification scheme would need to consider:
  1. a population’s perception of the current rate of scientific development in observed domains \cite{II_1973}
  2. a population’s perception of the current rate of technological development in observed domains \cite{II_1973}
  3. a population’s perception of the potential opportunity for change (e.g. alternatives are  believed to exist) \cite{II_1973}