The robustness of two widespread multifractal analysis methods, one based on detrended fluctuation analysis and one on wavelet leaders, is discussed in the context of time-series containing non-uniform structures with only isolated singularities. Signals generated by simulated and experimentally-realized chaos generators, together with synthetic data addressing particular aspects, are taken into consideration. The results reveal essential limitations affecting the ability of both methods to correctly infer the non-multifractal nature of signals devoid of a cascade-like hierarchy of singularities. Namely, signals harboring only isolated singularities are found to artefactually give rise to broad multifractal spectra, resembling those expected in the presence of a well-developed underlying multifractal structure. Hence, there is a real risk of incorrectly inferring multifractality due to isolated singularities. The careful consideration of local scaling properties and the distribution of Hölder exponent obtained, for example, through wavelet analysis, is indispensable for rigorously assessing the presence or absence of multifractality.Fil: Oswiecimka, Pawel. Polish Academy of Sciences; ArgentinaFil: Drozdz, Stanislaw. Cracow University of Technology. Faculty of Materials Engineering and Physics; PoloniaFil: Frasca, Mattia. University of Catania. Department of Electrical Electronic and Computer Engineering; ItaliaFil: Gebarowski, Robert. Cracow University of Technology. Faculty of Materials Engineering and Physics; PoloniaFil: Yoshimura, Natsue. Tokyo Institute of Technology. Institute of Innovative Research. FIRST; JapónFil: Zunino, Luciano José. Universidad Nacional de La Plata. Facultad de Ingeniería. Departamento de Ciencias Básicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Ópticas. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones Ópticas. Universidad Nacional de La Plata. Centro de Investigaciones Ópticas; ArgentinaFil: Minati, Ludovico. Universita degli Studi di Trento; Italia. Polish Academy of Sciences; Argentin
