One idea runs through this family: the whole, taken all together. To include is to fold a part into the whole; to generalize is to state what holds for the whole; a klal is both a general rule and an entirety; klali is "general", a michlala is a college (a whole body of study), a michlol is an ensemble. From the same letters comes the everyday kol, "all / every". Every word here is verified against pealim, niqqud included.
The same root runs through the verb system. Each binyan is a voice: it bends the one idea into active, passive, causative or reciprocal. Tap to hear.
Two binyanim carry the verbs: pa'al "to include" (fold into the whole) and hif'il "to generalize" (apply to the whole). The nif'al, pi'el and hitpa'el slots are not lexicalized for this root, so being-included is expressed with the participle כָּלוּל.
Same root letters, different noun moulds (mishkalim). The mould tells you the function: who does it, the act of doing it, or the thing produced.
Strip the prefixes, suffixes and vowels. Three consonants remain, and the meaning lives there.