We present TIGERScore, a\textbf {T} rained metric that follows\textbf {I} nstruction\textbf {G}
uidance to perform\textbf {E} xplainable, and\textbf {R} eference-free evaluation over a wide
spectrum of text generation tasks. Different from other automatic evaluation methods that
only provide arcane scores, TIGERScore is guided by natural language instruction to
provide error analysis to pinpoint the mistakes in the generated text. Our metric is based on
LLaMA-2, trained on our meticulously curated instruction-tuning dataset MetricInstruct which …