Obama, Barack, 1961- 88 Obesity 215 Obesity in children 54 Obituaries 137 Objectivity 138 Object-oriented programming (Computer science) 166 Obligations (Law) 120 Observation (Educational method) 71 Obstetrics 249 Ocampo, Satur C. 83 Occultism 86 Occupational diseases 65 Occupational mobility 57 Occupational therapy 193 Occupational training 290 Occupations 256 Ocean 88 Ocean engineering 50 Oceanography 390 Ocean travel 46 OCTA Research Team 377 Office buildings 72 Office layout 55 Office management 173 Office practice 132 Officers 330 Official Development Assistance 58 Officials and employees 4,712 Offshore structures 48 Oil industries 87 Oil spills 302 Old age 104 Old age pensions 119 Older people 920 Oligopolies 56 Olympics 117 Ombudsman 93 Oncology 59 Onions 137 Online education 63 Online journalism 86 Online social networks 230 Ontology 143 Opening 78 Open source software 70 Opera 150 Operas 918 Operating systems (Computers) 386 Operations research 668 Ophthalmology 130 Oplan Tokhang 63 Ople, Blas F. 130 Opposition (Political science) 82 Optical communications 87 Optical data processing 73 Optical engineering 71 Optical materials 48 Optical pattern recognition 61 Optical properties 51 Optics 147 Options (Finance) 118 Optoelectronic devices 50 Oral communication 497 Oral history 91 Oral interpretation 58 Oral tradition 127 Oratorios 97 Oratory 200 Orchestral music 413 Orchids 136 Ore deposits 51 Organic compounds 152 Organic farming 218 Organic fertilizers 57 Organization 809 Organizational behavior 1,437 Organizational change 1,365 Organizational effectiveness 636 Organizational learning 187 Organizational sociology 234 Organization and administration 70 Organized crime 55 Organ music 104 Oriental literature 70 Oriental Mindoro 124 Origami 55 Origin 269 Orphans 124 Orthodontics 137 Orthography and spelling 144 Orthopedics 149 Osteoporosis 107 Otolaryngology 80 Outdoor education 50 Outdoor recreation 113 Outlines, syllabi, etc 408 Overseas contract workers 103 Overseas Filipino Workers 1,490 Overtures 159 Oxidation 71