Table 3 Summary of statistical methods, their purposes, and corresponding research questions

Cluster analysis

To assess morphological similarities among different teff varieties

Do morphological similarities exist among teff varieties?

Pearson’s Chi-square test

To assess whether teff varieties grown across districts and kebeles are similar

Are teff varieties grown similar across districts?

Post hoc pairwise comparisons

To determine whether the similarity in teff varieties grown across districts and kebeles is statistically significant

Is the similarity in teff varieties between kebeles statistically significant?

Residuals from the Chi-squared

To determine whether teff varieties across different kebeles are similar

How do the observed teff variety distributions deviate from the expected values?

Generalized additive model (GAM)

To assess the effect of altitudinal differences on teff varieties

Does altitudinal difference affect teff varieties?

t-test

To examine differences in traditional knowledge among respondents

Is there a significant difference in traditional knowledge among respondents?

Ethnobotanical indices (RFC, UV, FL)

To compare the different uses of varietal mixture of teff (seregegna teff)

How do the different uses of seregegna compare?

Preference ranking

To compare the different uses of varietal mixture of teff with sole varieties

How do the advantages of seregegna compare to those of sole teff varieties?

Direct matrix ranking

To compare teff with other crops and seregegna (varietal mixture of teff) with other teff varieties

How do the attributes of teff compare to those of other crops, and how does seregegna compare to different teff types?