As it is formulated this question cannot be answered by a direct or fit-for-all solution. Innovation can refer to processes, technology, business models, managerial methods, products, services and other aspects of firms. Thus, it is important to specify first the category of innovation one is looking for and then to see what is the framework of evaluating the innovation the process, i.e. which kind of indicators people use in measuring the outcomes of innovation. For instance, if we consider innovation for products, then the number of patents could be a good indicator in measuring the innovation in different firms and then to compare them. The result is a continuum and there is no sharp line between low and high innovation. It is a matter of interpretation and of satisfying some requirements with respect to the goal of research. In conclusion, define first your goal of research and then the category of innovation processes you would like to study. Analyze the existing framework for measuring the innovation and the indicators already defined for that and just use them. However, innovation is a complex process and it combine usually several categories of aspects mentioned above, so one should be aware of how the measuring indicators are choosed, used, and interpreted. Also, it would be useful to look for some standardized indexes or already extensively used in practice.
We did some research in Croatia ( available on RG) and identified innovative and non innovative companies. Low innovative one coul be those companies whose innovations are moderate and appear as reaction to industry or market changes?