Herein we report experimental results on a wide variety of common, linear flexible polymers in solution in an attempt to confirm prior reports of abrupt ’conformational transitions’ for these materials. Such transitions have been claimed by numerous authors, and they have been reported to reflect sudden conformational changes brought about, in most cases, by varying temperature. Methods used both in our work and earlier work include viscometry, differential refractometry and size exclusion chromatography. We observed no evidence of such conformational transitions and conclude that in reality such events are probably rare. We believe that many prior reports of such sudden changes in shape/size are probably mistaken because of the failure of some authors to take into account realistic experimental errors during data analysis and interpretation.