Assessment means many things to many people. There is a plethora of terms and definitions. To measure science-learning outcomes at skills level, assessment was modified and restructured not only in form and context, but in vocabularies and nomenclatures. Thus, there emerged different forms, like alternative, authentic and performance assessments, which are labeled the most suitable for assessing science process skills demonstrated and developed by students during science activities. The author of this paper took a critical look at these various forms and found them not being strong and precise enough for that purpose. What is demanded from the students and teachers in the various forms of assessments differs not much from those of the conventional paper-and-pencil types. Or, at best, it is the product of investigation written on paper and marked by conference examiners. The disadvantages of this conventional practice are much. The author is therefore advocating on-the-spot assessment of skills as complements and supplements to these others. The advantages are overwhelming and are stated in the body of the paper. (Contains 3 tables.)