# Automatic Era Identification in Classical Arabic Poetry
## 1 Introduction  
Pre-Islamic poetry was transmitted orally. Classical critics began to collect and transcribe these poems only about two centuries after the birth of Islam, in the 8 th century C.E, assembling the poems into collections called diwas. Yet the authenticity of these poems is an open research question to this day. Some poems may indeed belong to the pre-Islamic era but might have been attributed to the wrong poet, or they could be written later in time. In the twentieth century, scholars of Arabic poetry claimed that at least some of the poemsattributed to the pre-Islamic era were composed after the appearance of Islam. Several works, mainly those by [PERSON] [1], [PERSON] [2] and [PERSON] [3], discuss possible reasons for such errors. The harshest argument against the authenticity of the poems attributed to the pre-Islamic era was made by [PERSON] [4], claiming that the whole corpus of supposedly pre-Islamic literature had been written after the advent of Islam. Other scholars mitigated this criticism, while still suggesting that some of the poems attributed to pre-Islamic or _mubadram_ poets (i.e., poets who lived in both eras: pre-Islamic and early Islamic) should be attributed to poets from later periods [5]. In this study, our goal is to investigate how and to what extent it is possible to automatically determine whether a poem that is attributed to the pre-Islamic era originates from that period. While we do not expect an automatic approach to resolve a dispute among domain experts, we believe that text analysis can serve as a useful supplementary tool for researchers, highlighting individual poems as typical or atypical of the pre-Islamic era. Towards that aim, we trained machine learning models for era prediction, where training involves the processing of various descriptive statistics of a large number of poems for which there is no dispute. For the purpose of this study, we constructed a dataset that includes several diwans by the most famous poets of each era, which we make available to the research community. There are four periods that are represented in the dataset. The pre-Islamic period pertains to poems composed by poets who lived in the 6 th century CE. The second period is of the _mubadram_ poets, who were born in the pre-Islamic era (in the 6 th century CE) and lived through the 7 th century CE. It is therefore challenging to determine whether these poems were composed before Islam or slightly after it. The third period is the Umayyad period, which began in the year 661 and ended in 750 CE. Lastly, the 'Abbasid period is the longest, ranging from 750 CE until the year 1258 CE. In this study, we mainly distinguish between the 'Abbasid period and the preceding periods, considering the poems which were authored during the first three periods as pre-' Abbasid. Most of the poems in the dataset are linked with the authoring poets and their respective period with high certainty (termed as 'original'). We use these poems for the learning, running, and evaluation of the era prediction models. In addition, the dataset includes a minority of poems associated with a poet and era, but which are marked as 'under dispute'. We examine the degree to which the learned models agree with the era that is attributed to those poems. The disputable poems are all affiliated with the pre-' Abbasid periods, but some of them might have been composed later, during the 'Abbasid period. Due the cost of manual transcription, the dataset is limited in size, yet it includes several hundreds of poems. Overall, the poems are attributed to thirteen poets with varying numbers of poems, ranging between 25 to 900 per poet. Considering this imbalance over poets, we focused our efforts on era identification rather than on poet identification (see Table 1 for details). In particular, our main classification experiments aim to distinguish between poems composed during the 'Abbasid period and those from the pre-' Abbasid periods, as well as to differentiate between the various periods that preceded the 'Abbasid era.