The primary aim of the study was to determine the strength of correlations between physical illness and stress, mood, and coping strategies when computed from longitudinal data using different methods of calculation. Sixty-one female college students completed weekly measures of stress, positive and negative mood, coping, and symptoms of illness for 6 weeks. The primary outcome measure was correlations computed from longitudinal data using different statistical methods. Significant correlations were found between physical symptoms of illness and measures of stress and negative mood. Furthermore, there were differences in the magnitude of the correlations depending on how they were calculated. The SPSS data file is formatted with each participant having one row of data for each week of responses.