What does the word “conscientious” mean in the following sentence? although she was conscientious, or careful, a few errors slipped by.

Shauna has collected a variety of sources for her research about charlie chaplin’s impact on american cinema. in performing her preliminary evaluation of each source, shauna should-thoroughly review and examine the content.-perform a quick search to determine the author’s reliability.-check whether the author agrees with experts on the subject.-decide whether it will be useful in her final essay.