ejecting liquid droplets from a liquid ejection head including a plurality of liquid droplet ejection ports, toward a first recording medium situated at a first distance from an ejection surface of the liquid ejection head in such a manner that the liquid droplets are deposited on the first recording medium;

determining an amount of a first droplet deposition position error with respect to an ideal droplet deposition position on a recording surface of the first recording medium, according to a droplet deposition result obtained from the liquid droplets on the first recording medium;

ejecting liquid droplets from the liquid ejection head toward a second recording medium situated at a second distance, which is different from the first distance, from the ejection surface in such a manner that the liquid droplets are deposited on the second recording medium;

determining an amount of a second droplet deposition position error with respect to an ideal droplet deposition position on a recording surface of the second recording medium, according to a droplet deposition result obtained from the liquid droplets on the second recording medium; and

performing calculation for separating a first error component caused by errors in relative positions between the liquid ejection head and each of the first and second recording media, and a second error component caused by an error in an ejection direction of each of the liquid droplet ejection ports, from the determined amounts of first and second droplet deposition position errors; and

obtaining error information relating to at least one of the first and second error components.