Realistic perception of our own knowledge is important in various areas of everyday life, yet previous studies reveal that our self-perception is full of shortcomings. The present study focused on general overestimation of knowledge and differences between experts and the less-skilled (The Dunning-Kruger effect), self-perceived knowledge of non-existing concepts (overclaiming), and the illusion of knowledge. These phenomena were tested with an instrument which measured the actual knowledge of different domains (grammar, literature, and nanotechnology), as well as self-assessed knowledge. Results showed that, on average, participants overestimated their absolute performance, but not their performance relative to others. Furthermore, the bottom quartile overestimated their absolute and their relative performance most, while the top quartile perceived their absolute performance most accurately and substantially underestimated their relative performance. Results related to overclaiming showed that 56% of respondents claimed knowledge of at least one non-existent book and that the extent of overclaiming was substantially correlated with self-perceived expertise. Lastly, results showed that an increased quantity of information about nanotechnology led to a false certainty in answering questions from this area. Povzetek: Realistično zaznavanje lastnega znanja je pomembno na različnih področjih vsakdanjega življenja, a pretekle raziskave razkrivajo, da je naša samozaznava v resnici polna pomanjkljivosti. Pričujoča študija se je osredotočila na splošno precenjevanje znanja in razlike med eksperti ter slabšimi reševalci (Dunning-Krugerjev učinek), na poznavanje neobstoječih konceptov in na iluzijo znanja. Omenjene pojave smo preverjali z instrumentom, ki je vseboval elemente objektivnega ocenjevanja znanja in samoocene znanja na različnih področjih -slovnica, književnost in nanotehnologija. Rezultati so pokazali, da so udeleženci v povprečju precenjevali svoj absolutni dosežek, ne pa tudi svojega položaja v vzorcu. Nadalje so tisti iz spodnjega kvartila najbolj precenjevali svoj absolutni in relativni dosežek, medtem ko so tisti iz zgornjega kvartila svoj absolutni dosežek ocenjevali najtočneje, ob tem pa znatno podcenjevali svoj relativni dosežek. Rezultati, vezani na poznavanje neobstoječih konceptov, so pokazali, da je 56 % udeležencev zatrdilo poznavanje vsaj enega neobstoječega literarnega dela, pri tem pa se je z ravnjo poznavanja neobstoječih konceptov zmerno povezovala samozaznana kompetentnost. Nazadnje so rezultati pokazali tudi to, da je povečana kvantiteta informacij o nanotehnologiji vodila do občutka lažne gotovosti pri odgovarjanju na vprašanja iz tega področja.
KeywordsKljučne besede: precenjevanje znanja, Dunning-Krugerjev učinek, poznavanje neobstoječih konceptov, iluzija znanja