This dataset comprises the transcripts of participants' speech of the so called `Rejection experiment' described in Förster F., Saunders J. & Nehaniv C. L. (2017) Robots that Say `No'. Affective Symbol Grounding and the Case of Intent Intepretations. IEEE Transactions on Cognitive and Developmental Systems The data set consists of 50 transcripts based on ten participants and five sessions per participant. Participants are only disguishable by their participant ID. Each participant completed 5 sessions of approximately 5 minutes each, see file `session_durations.txt' for the precise length of each session. The files names encode participant ID, session number, and date of session. Example: P06s2-091211.txt contains the transcript of participant P06's speech produced during P06's second session. The session took place at the 9th of December 2011. All transcripts were manually produced mainly for the purpose of improving speech recognition and in order to allow for subsequent prosodic analysis of the corresponding audio recordings. Line breaks roughly constitute the transcribers subjective judgement of the end of an utterance. As hinted at above, the presented transcripts were created meant for speech recognition and other machine leaning purposes in conjunction with the original audio files rather than being useful for human analysts. The authors therefore intend to provide full conversation analytical transcripts in the future which would susequently supersede the present transcripts. Acknowledgement: The experiments within which the given data set was gathered were part of the EU Integrated Project ITALK ("Integration and Transfer of Action and Language in Robots") and funded by the European Commission under contract number FP-7-214668.