  We have used many decades of visual observations from the AAVSO International
Database, and the AAVSO time-series analysis package VSTAR, to study the
long-term changes in period, amplitude, and mean magnitude in about 30 normal
pulsating red giants (PRGs) i.e. those without large secular changes in period,
as well as a few of the rare PRGs which do have such secular period changes.
The periods of the typical PRGs "wander" on time scales of about 40 pulsation
periods -- significantly longer than the time scales of amplitude variation
which are 20-35 with a mean of 27 pulsation periods. We have also studied the
range and time scale of the long-term changes in pulsation amplitude and mean
magnitude, as well as period, and looked for correlations between these.
Changes in mean magnitude are larger in stars in stars with larger mean
amplitude, but correlate negatively with changes in amplitude. There is a weak
positive correlation between the long-term period changes and amplitude
changes. The causes of these three kinds of long-term changes are still not
clear. We note, from the presence of harmonics in the Fourier spectra, that the
longest-period PRGs have distinctly non-sinusoidal phase curves. For studying
PRGs, we demonstrate the advantage of studying stars with minimal seasonal gaps
in the observations, such as those near the celestial poles. We studied Z UMi,
misclassified as a possible Mira star, but actually an R CrB star. We
determined times of onset of 16 fadings. We were not able to determine a
coherent pulsation period for this star at maximum, with an amplitude greater
than 0.05. We did, however, find that the times of onset of fadings were
"locked" to a 41.98-day period -- a typical pulsation period for an R CrB star.
