Method for determining the influence of least a first and a second experimental parameter on a liquid chromatography protocol for purifying one or more target molecules from a sample, comprising the steps: —performing chromatography purifications of the sample at a plurality of different experimental conditions where at least the first and the second experimental parameter each are varied over a predetermined range, each purification being registered as a chromatogram by monitoring an output parameter indicative of the purification result during the purification; and—displaying in a graphical user interface at least a subset of the registered chromatograms as chromatogram-miniatures in an evaluation diagram wherein the position of each displayed chromatogram-miniature is determined by the experimental parameters for the corresponding purification, thereby allowing a user to visually determine trends and the influence of the experimental parameters on the liquid chromatography protocol.