In this thesis magneto-thermoelectric effects are investigated in a systematic way to separate the transverse spin Seebeck effect from other parasitic effects like the anomalous Nernst effect. In contrast to the first studies found in the literature, in NiFe thin films a contribution of the transverse spin Seebeck effect can be excluded. This surprising outcome was crosschecked in a variety of different sample layouts and collaborations with other universities to ensure the validity these results. In general, this thesis solves a long time discussion about the existence of the transverse spin Seebeck effect in NiFe films and supports the importance of control measurements for the scientific community. Even if such "negative" results may not be the award winning ones, new discoveries should be treated with constructive criticism and be checked carefully by the scientific community.